Aaron Ramsey has been ruled out for the rest of Arsenal's season, including Thursday's Europa League clash with Valencia.
Wales international Ramsey is sidelined with the hamstring injury sustained in the quarter-final second-leg win over Napoli and, ahead of his summer move to Juventus, will now sit out the remainder of the season.
Arsenal's coach, Unai Emery, confirmed the news in a press conference ahead of Thursday's clash at the Emirates: "We can't use him, injuries come for players like that and we have players who can play.
"But he was in a good moment when he took this injury. I had a good experience with him, he transmitted his energy and his heart is red like Arsenal.
Look forward to seeing you at Emirates Stadium on Sunday, Aaron ❤️💛💙 pic.twitter.com/pKhmRq1B0M— Arsenal FC (@Arsenal) May 1, 2019
"I wanted to enjoy this with him. I said to him, I wanted to do something important with you.
"Aaron played so many years here, he is so important for the club and the players because he did so much for the new players.
"He signed for Juventus but he is still a professional and always fought for the club. Some other players might stop fighting – but he loves this club so he stayed 100 per cent.
"He has a great mentality. I will miss him a lot – we have good memories."
Also a doubt for the Gunners is Nacho Monreal, who has a calf problem and will face a late fitness test ahead of the semi-final first leg at Emirates Stadium.
Denis Suarez is out with a groin injury, while Hector Bellerin (knee), Rob Holding (knee) and Danny Welbeck (ankle) are still recovering from long-term problems.
Arsenal host Los Che before heading to Mestalla for the return leg on May 9.