Manager: Roberto Di Matteo
Ground: Stamford Bridge Capacity: 41,837
Last season: 6th, Premier League
Champions League best: Winners (2012)
Key player – Fernando Torres: Torres has had a tough time since moving to London from Liverpool in 2011, but has finally shaken off his poor form and resembles the potent force he once was. If the Spaniard can begin to fire on all cylinders again, then Chelsea will have a big advantage when looking to defend their European title
Photograph: Tom Jenkins for the Guardian
Manager: Tito Vilanova
Ground: Camp Nou Capacity: 99,354
Last season: 2nd, La Liga
Champions League best: Winners (1992, 2006, 2009, 2011)
Key player – Lionel Messi: The defeat to Chelsea in the semi-finals last season will have hurt Barcelona, but they remain the envy of every side in Europe and with Messi still at his best, few would bet against them securing another title next May. Messi scored 50 league goals in 37 games during 2011-12, which speaks for itself Photograph: Gustau Nacarino/REUTERS
Manager: José Mourinho
Ground: Santiago Bernabéu Capacity: 85,454
Last season: 1st, La Liga
Champions League best: Winners (1998, 2000, 2002)
Key player – Cristiano Ronaldo: Scored a remarkable 46 goals in 38 league appearances for the Spanish champions last season, surpassing Ferenc Puskas's Madrid record by reaching 101 goals in 92 games. Ronaldo already has one Champions League medal to his name, after winning the 2007-08 competition with Manchester United, but he will be the driving force behind Los Blancos again this season Photograph: Denis Doyle/Getty Images
Manager: Sir Alex Ferguson
Ground: Old Trafford Capacity: 75,765
Last season: 2nd, Premier League
Champions League best: Winners (1999, 2008)
Key player – Robin van Persie: Van Persie will be hungry to add a first Champions League medal to his name, although he already has European success on his CV, having won the Uefa Cup in 2002 with Feyenoord. His goals could be crucial this season following his move from Arsenal, and if he can form an understanding with Wayne Rooney then United will be a formidable force
Photograph: Matthew Ashton/AMA/Corbis
Manager: Jupp Heynckes
Ground: Allianz Arena Capacity: 69,901
Last season: 2nd, Bundesliga
Champions League best: Winners (2001)
Key player – Arjen Robben: The Dutch winger has not enjoyed the healthiest relationship with Bayern since his arrival from Real Madrid in 2009, missing the majority of the 2010-11 season after sustaining an injury with Holland and seeing his extra-time penalty saved by Petr Cech in May's final. But he still has the ability to make the difference Photograph: Daniel Ochoa De Olza/AP
Manager: Arsène Wenger
Ground: Emirates Stadium Capacity: 60,361
Last season: 3rd, Premier League
Champions League best: Runners-up (2006)
Key player – Santi Cazorla: The attacking midfielder has made an immediate impact after being brought in from Málaga, and seems to be the outlet for almost every Arsenal attack. Goals may be hard to come by following the departure of Robin van Persie, but Cazorla will hope to take up some of the responsibility in this department, sitting just behind the striker and taking Arsenal's set pieces
Photograph: Marc Atkins/BPI/Corbis
Manager: Vitor Pereira
Ground: Estádio do Dragão Capacity: 50,399
Last season: 1st, Primeira Liga
Champions League best: Winners (2004)
Key player – Hulk: It is eight years since Porto won the competition under José Mourinho but they remain a mainstay in the competition. If they are to progress to the latter stages this season then their striker Hulk will most likely be at the heart of their campaign. The 26-year-old brute of a centre forward has been targeted by Europe's top clubs but Porto will not sell their captain without a fight Photograph: Jose Coelho/EPA
Manager: Massimiliano Allegri
Ground: San Siro Capacity: 80,018
Last season: 2nd, Serie A
Champions League best: Winners (1994, 2003, 2007)
Key player – Giampaolo Pazzini: Max Allegri saw Antonio Cassano suffer a stroke on a team flight last season, and has since exchanged the fiery forward with Internazionale's Pazzini. Milan will be relying on his goals to fire them through after the Rossoneri were beaten by Barcelona in last year's quarter-finals Photograph: Matteo Bazzi/EPA
Manager: Mauricio Pellegrino
Ground: Mestalla Capacity: 55,000
Last season: 3rd, La Liga
Champions League best: Runners-up (2000, 2001)
Key player – Roberto Soldado: The 27-year-old striker has signed a new contract with Los Che until 2017 and is likely to continue in his leading role up front. The club is understood to be on more reasonable financial ground having sold off a number of prized assets in recent years Photograph: Manuel Queimadelos Alonso/Getty Images
Manager: Jorge Jesus
Ground: Estádio da Luz Capacity: 65,647
Last season: 2nd, Primeira Liga
Champions League best: Quarter-finals (2006, 2012)
Key player – Oscar Cardozo: Benfica may have been pipped to the post in the league last season but Cardozo still finished top scorer and is a lethal presence in and around the penalty area. When Benfica are on song, the Paraguay international is usually treated to flurry of scoring opportunities and he rarely fails to dispatch them Photograph: Jose Sena Goulao/EPA
Manager: Mircea Lucescu
Ground: Donbass Arena Capacity: 52,187
Last season: 1st, Ukrainian Premier League
Champions League best: Quarter-finals (2011)
Key player – Douglas Costa: Shakhtar have a plethora of talented Brazilian players at their disposal, many of whom have been courted by clubs in England, Spain and Italy. Douglas, 21, joined the Ukrainian champions from Gremio in 2010 and the attacking midfielder's performances have already made him a key part of the side Photograph: Alexander Khudoteply/AFP/Getty Images
Manager: Luciano Spalletti
Ground: Petrovsky Stadium Capacity: 21, 570
Last season: 1st, Russian Premier League
Champions League best: Last 16 (2012)
Key player – Aleksandr Kerzhakov: If Zenit are to go one better than their best ever European campaign, when they made the final 16 last season, then the goals of Kerzhakov will be paramount. The 29-year-old striker is the third-highest scorer in Russian top-flight history and signed a new four-year contract in August Photograph: Stringer/REUTERS
Manager: Huub Stevens
Ground: Veltins-Arena Capacity: 61,673
Last season: 3rd, Bundesliga
Champions League best: Semi-finals (2011)
Key player – Klaas-Jan Huntelaar: Huntelaar has been prolific for Schalke since his disappointing spells with Real Madrid and Milan. He scored two second-half goals on the final day of last season against Werder Bremen to ensure Schalke's place in the Champions League and has now established himself as Holland's go-to striker, even when Robin van Persie is fit Photograph: Michael Sohn/AP
Manager: Roberto Mancini
Ground: Etihad Stadium Capacity: 47,726
Last season: 1st, Premier League
Champions League best: Group stage (2011)
Key player – Carlos Tevez: City's bow in Europe's elite club competition was a disappointing one last season but Roberto Mancini will be hoping his players learn from that experience. Tevez 'refused' to play during a group stage match at Bayern Munich last September and nobody would have expected him to wear the blue of City again. But he has started the campaign well and will be a key player
Photograph: Tom Jenkins for the Guardian
Manager: José Peseiro
Ground: Estádio Municipal Capacity: 30,154
Last season: 3rd, Primeira Liga
Champions League best: Group stage (2010)
Key player – Lima: After scoring 20 goals last season for Braga, the striker has become a key member of the squad and he finished as the Primeira Liga's top scorer. His nine European goals suggest he has the experience to trouble continental defences too and he was an important member of the team that finished as runners-up in the Europa League in 2011 Photograph: HUGO DELGADO/EPA
Manager: Yuri Syomin
Ground: Olimpiysky National Sports Complex Capacity: 70,050
Last Season: 2nd, Ukrainian League
Champions League best: Semi-finals (1999)
Key player – Ideye Brown: The former Sochaux striker, signed on a free transfer last year, scored three goals in four appearances during the club's qualifying run. The 23-year-old Nigerian has three caps for his country and sealed his club's qualification with a neat chip to knock Mönchengladbach out Photograph: PATRIK STOLLARZ/AFP/Getty Images
Manager: Leonardo Jardim
Ground: Karaiskakis Stadium Capacity: 32,115
Last season: 1st, Superleague
Champions League best: Quarter-finals (1999)
Key player – Rafik Djebbour: Having joined Olympiakos in January 2011, Djebbour has gone on to become a mainstay of the side after spells with a number of Greek clubs. The Algerian forward scored his first ever Champions League goal against Dortmund last season and could prove influential again Photograph: Vladimir Rys Photography/Getty Images
Manager: Frank de Boer
Ground: Amsterdam Arena Capacity: 52,342
Last season: 1st, Eredivisie
Champions League best: Winners (1995)
Key player – Christian Eriksen: Eriksen looked bright during Denmark's Euro 2012 campaign in the summer and the prodigious young talent could go from strength to strength with Ajax. The 20-year-old provided 19 assists for the champions in the Eredivisie last season and it may not be too long before he is tempted away from Amsterdam Photograph: Olaf Kraak/AFP/Getty Images
Manager: John van den Brom
Ground: Constant Vanden Stock Stadium Capacity: 21,845 for European matches
Last season: 1st, Belgian Pro League
Champions League best: Last 16 (2001)
Key player – Dieudonné Mbokani: Since joining Anderlecht in 2011, the centre-forward's career has been beset by injury and tragedy – his five-month-old son died of a heart attack shortly after he signed. He still managed 15 goals in 30 appearances for the club and has four in three during this year's qualifying stages Photograph: LAURENT DUBRULE/Reuters
Manager: Antonio Conte
Ground: Juventus Stadium Capacity: 41,000
Last season: 1st, Serie A
Champions League best: Winners (1996)
Key player – Andrea Pirlo: The 33-year-old still has the ability to pull the strings in midfield, and he played an integral role in Juve's league triumph last season following his switch from Milan. He had a fine European Championship with Italy during the summer where he tore England to shreds in the quarter-finals Photograph: Stringer/REUTERS
Manager: Leonid Fedun
Ground: Luzhniki Stadium Capacity: 78,360
Last season: 2nd, Russian Premier League
Champions League best: Quarter-finals (1996)
Key player – Kim Kallstrom: The Swedish midfielder has won over 90 caps for his country and his experience will be a great asset to the Russian club if they are to progress from the group stage for the first time in 16 years. Meanwhile, the identical twins Kirill and Dmitri Kombarov have both provided goals from midfield in recent years Photograph: Tolga Bozoglu/EPA
Manager: Carlo Ancelotti
Ground: Parc des Princes Capacity: 48,712
Last season: 2nd, Ligue 1
Champions League best: Semi-finals (1995)
Key player – Zlatan Ibrahimovic: Always an enigma wherever he plays, Ibrahimovic joined the Parisian revolution this summer, the latest big-money signing to arrive at the Parc des Princes. PSG have started the season slowly but with Ibrahimovic in their attacking ranks they have a player capable of pretty much anything. If they get the best out of him then other teams should beware Photograph: Jacques Demarthon/AFP/Getty Images
Manager: Rudi Garcia
Ground: Grand Stade Lille Métropole Capacity: 50,186
Last Season: 3rd, Ligue 1
Champions League best: Last 16 (2007)
Key player – Salomon Kalou: After losing Eden Hazard to Chelsea, goals may be in short supply for Lille this season. Striker Moussa Sow has left too, meaning Kalou, the former Chelsea forward, will need to prove his worth to his new club Photograph: FRANCOIS LO PRESTI/AFP/Getty Images
Manager: Fatih Terim
Ground: Turk Telekom Arena Capacity: 52,652
Last season: 1st, Super Lig
Champions League best: Quarter-finals (1994, 2001)
Key player – Johan Elmander: The Swedish forward moved to Istanbul last summer on a free transfer from Bolton Wanderers and scored 12 goals in 36 league matches as Galatasaray marched to the Turkish title. Now 31, Elmander will relish this shot at the European big time and use his physical approach to impose himself on the opposition Photograph: Bulent Kilic/AFP/Getty Images
Manager: Neil Lennon
Ground: Celtic Park Capacity: 60,832
Last season: 1st, Scottish Premier League
Champions League best: Last 16 (2007, 2008)
Key player – Gary Hooper: The forward's goal against Helsingborg sealed Celtic's progress into the group stage of the competition, something the manager, Neil Lennon, called 'his greatest achievement in football'. The 24-year-old has five goals in 11 European appearances and is likely to be a more useful outlet than Georgios Samaras Photograph: Steven Paston/Action Images
Manager: Jürgen Klopp
Ground: Signal Iduna Park Capacity: 80,720
Last season: 1st, Bundesliga
Champions League best: Winners (1997)
Key player – Robert Lewandowski: The Polish striker is regarded as one of the finest front men on the continent and spearheaded Dortmund to the Bundesliga title last season. He was named the league's player of the season after finishing the campaign with 22 goals, and Dortmund will be hoping he can help improve on their Champions League efforts during 2011-12, when they finished bottom of their group Photograph: Christof Koepsel/Bongarts/Getty Images
Manager: Viktor Goncharenko
Ground: City Stadium Capacity: 5,402
Last season: 1st, Belarusian Premier League
Champions League best: Group stage (2008, 2011)
Key player – Alexander Hleb: Much travelled, richly experienced but largely underwhelming during his spells at Arsenal, Barcelona and Birmingham, Hleb has returned to the club at which his senior career started. His European experience should count for much for the Belarusian side Photograph: OLIVER WEIKEN/EPA
Manager: Ante Cacic
Ground: Stadion Maksimir Capacity: 38,923
Last season: 1st, Croatia Prva HNL
Champions League best: Group stage (1998, 1999, 2011)
Key player – Fatos Beqiraj: The Montenegrin striker has scored 24 goals in 55 appearances for Zagreb, including 15 in 28 to become last season's top league scorer. He also thumped home a header against Real Madrid during the side's 6-2 defeat at the Bernabéu in 2011 Photograph: JURE MAKOVEC/AFP/Getty Images
Manager: Ioan Andone
Ground: Dr Constantin Radulescu Capacity: 23,500
Last season: 1st, Liga 1
Champions League best: Group stage (2009, 2011)
Key player – Modou Sougou: The Senegalese winger was a favourite of André Villas-Boas when he played in the Portuguese league for Académica de Coimbra and has impressed for Cluj since joining in 2011. His three goals in four appearances during Cluj's qualifying campaign have since marked him out as one of their most valuable assets Photograph: Mircea Rosca/AP
Manager: Manuel Pellegrini
Ground: La Rosaleda Capacity: 29,500
Last season: 4th, La Liga
Champions League best: N/A
Key player – Martin Demichelis: The Argentinean warhorse has won 11 titles in Germany playing for Bayern Munich and his European experience will be vital for Malaga in their first Champions League appearance. The defender scored the club's first ever Champions League goal in qualifying against Panathinaikos and will be crucial, as will the forward Júlio Baptista when he returns from injury Photograph: Panagiotis Moschandreou/EPA
Manager: René Girard
Ground: Stade de la Mosson Capacity: 32,900
Last season: 1st, Ligue 1
Champions League best: N/A
Key player – Younès Belhanda: Montpellier's miraculous march to the French title was in no small part down to Olivier Giroud, but since his departure to Arsenal, the goalscoring burden will now fall on other shoulders. The Moroccan winger Belhanda may only be 22 but was nominated for Ligue 1's player of the season award and won the young equivalent Photograph: Stephane Mahe/REUTERS
Manager: Kasper Hjulmand
Ground: Farum Park Capacity: 10,100
Last season: 1st, Danish Superliga
Champions League best: N/A
Key player – Morten Nordstrand: Nordsjaelland stunned Danish football when they clinched the title on the final day of the season to end Copenhagen's three-year hold on the title. Nordsjaelland's style does not rely on a typical centre forward but the return of the 29-year-old Nordstrand will provide them with that extra firepower up front during their debut Champions League campaign Photograph: Philippe Huguen/AFP/Getty Images
