Villarreal will be without key midfielder Marcos Senna for this week's Champions League trip to London to face Arsenal.
The Spain international will miss the return leg of the quarter-final tie after suffering a hamstring problem during Saturday's 2-0 home defeat to Malaga.
Senna had scored the Yellow Submarine's goal in the 1-1 first-leg stalemate at El Madrigal on Tuesday.
Coach Manuel Pellegrini has also lost Santi Cazorla and Mati Fernandez to injury in recent weeks and has admitted the timing of the blows is unfortunate.
"Obviously when you lose you are worried and must work hard to improve, but it's also true that the injuries have affected us and causing us problems," claimed the Chilean.
Meanwhile, Atletico Madrid's Czech Republic defender Tomas Ujfalusi has distanced himself from reports linking him with a move back to Italy to join Juventus.
The rugged 31-year-old centre-back enjoyed a successful four-year stint with Fiorentina before heading to Spain last summer and he insists that he is happy with Atletico.
He told Radio Kiss Kiss: “I feel plenty of nostalgia for Italy. I played there for four years with Fiorentina and I am very attached to the country.
“I'm very glad that Juventus are interested in me, but I'm doing very well in Madrid.
“It's no secret, however, that I would like to finish my career in Florence, where I spent the best moments of my life.”
Coach Pep Guardiola has rubbished suggestions that Barcelona's 4-0 first-leg advantage means the return leg of their Champions League quarter-final clash with Bayern Munich on Tuesday will be a formality.
"It's a good test for us. We need to go there with care," he warned. "Bayern are capable of scoring four goals and even more so when they are hurt like they are.
"I don't believe the declarations that are coming out about the fact they have already given the game up. We have to go there thinking we need to win the game."