Aaron Ramsey has been ruled out of Arsenal's Europa League clash with Valencia on Thursday, while Nacho Monreal is a doubt.
Wales international Ramsey is still sidelined with the hamstring injury sustained in the quarterfinal second-leg win over Napoli and, although he could return to action before moving to Juventus at the end of the season, he remains unfit.
Read | Arsenal wants to be world's best, says Unai Emery
Monreal, meanwhile, has a calf problem and will face a late fitness test ahead of the semifinal 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.
The Gunners host Marcelino's side before heading to Mestalla for the return leg on May 9.