Manchester United enjoyed an eye-catching summer transfer window, adding three legitimately world-class players to a squad already considered among the best in Europe.

Jadon Sancho has finally arrived to solve a problem many of Ole Gunnar Solskjaer 's predecessors have struggled with: the right wing. Plenty have tried and failed to fill the void left by Cristiano Ronaldo in 2009 - Angel Di Maria and Henrikh Mkhitaryan the most high-profile - but Sancho is back in Manchester to end those struggles. Oh, and Ronaldo himself. More on him shortly.

Raphael Varane has addressed the berth alongside Harry Maguire, bringing quality and pedigree to a talented backline without many trophies to their name. The Frenchman has won every top honour the game offers and will have the experience to guide his fellow defenders through adversity.

The biggest name of the three is, of course, Cristiano Ronaldo. Ronaldo is not the same player who departed United 12 years ago, though returns with four Champions League trophies under his belt, a few move league titles to boot and plenty of personal accolades.

There is no doubt Ronaldo will win games for United this season, but the serious deficiency in the heart of midfield will hold his new side back.

United were widely expected to pursue a defensive midfielder this summer due to their lack of quality in the centre. Whilst their options are good, improvements can - and should - have been made over the summer, and was a key idea for Solskjaer to address..

Declan Rice is the much-desired target, but United will have to do with Fred, Scott McTominay and Nemanja Matic for the remainder of the season.

Paris Saint-Germain, everyone's team to beat in Europe, have no such problems.

In a breathtaking window, PSG have added six new players to slot into their first XI. None more spectacular than Lionel Messi, who has now joined forces with Kylian Mbappe and Neymar to create the most feared triumvirate in Europe.

It is not just in attacking areas where the French side have strengthened. Achraf Hakimi, Sergio Ramos and Euro 2020 goalkeeper of the tournament, Gianluigi Donnarumma will see head coach Mauricio Pochettino set up with three central defenders complemented by wing-backs, providing much-needed defensive stability behind the considerable quality in attack.

If Pochettino finds the magic formula to make this PSG side gel, there is no doubt that United will face one of the most complete and truly devastating sides in European football history.

Before Solskjaer's side can think about facing Europe's top teams at the latter stages of the Champions League, they will have to get through a tricky group featuring Villarreal, the side that beat them just months ago in the Europa League final.

United should expect to reach the knockout phase, an improvement upon last season - and a semi-final spot should be the aim thanks to a summer of big spending on bigger names. It all kicks off on the continent next week.

However, with Ronaldo not getting any younger, there is pressure on Solskjaer to deliver silverware promptly.