Valencia will be without injured Argentina midfielder Ever Banega for four to six weeks.
Banega hurt his right knee during the first half of Tuesday's 3-1 Champions League win over Bayer Leverkusen, and medical scans on Wednesday confirmed a grade two sprain.
The club expects Banega to be 100 percent come the start of 2012, but he will miss the Spanish team's last two Group E matches.
Valencia is third, three points behind leader Chelsea and one point behind Leverkusen with two games remaining.
The 23-year-old Banega had started all 13 of Valencia's games this season.
Valencia is fourth in league play, four points behind leader Real Madrid.