Arsenal are preparing for one of the biggest games of their season, a Europa League semi-final first leg on Thursday night.
The Gunners face Unai Emery's Villarreal away from home as they look to establish an advantage ahead of the second leg at the Emirates Stadium next week.
With European qualification all-but impossible in the Premier League, Arsenal need to win this competition if they want to be playing European football next season.
And with that in mind, and given their poor home form this season, they cannot afford to give themselves a mountain to climb in the second leg against a Villarreal side who are unbeaten in the Europa League this season, winning 11 and drawing one.
Ahead of the game, the Gunners put in the hard yards at London Colney before setting off to Castellon, and below we have rounded up three things we noticed from the latest session.
Injured stars return
Arsenal fans will have been delighted to hear four of their key stars are 'in contention' to feature on Thursday night.
"They are all in contention all of them," said Arteta in his pre-match press conference.
"Including Aubameyang, including Laca, including Kieran. They are all in contention for the game."
Not only are they in contention but all three, plus David Luiz, appeared to take part in full training on Wednesday ahead of travelling to Castellon de la Plana.
That's a huge boost for the Gunners.
Youngsters feature
After agreeing a new contract with Arsenal, promising youngster Folarin Balogun has hinted on social media that he will be involved on Thursday.
He could prove important given there will be question marks over the fitness of Lacazette and Aubameyang, and indeed whether they can make it through a full game, even if they do manage to start.
Balogun featured in training ahead of the trip to Spain, and as you would expect, Eddie Nketiah also featured prominently.
Willian stakes his claim
Willian hasn't featured an awful lot of late, playing just 40 minutes in the last six Premier League games.
Arteta has plenty of options, with Nicolas Pepe, Bukayo Saka and Gabriel Martinelli, all in contention to start at Villarreal, as well as Lacazette or Aubameyang.
Willian has found himself down the pecking order amid that intense competition, but he looked as though he had a point to prove in training, appearing to nutmeg Martinelli.
The Brazilian veteran is not likely to start on Thursday, but he will be desperate to play a part.
