Chelsea are anxiously awaiting news on Didier Drogba after the striker suffered suspected knee ligament damage during Wednesday's goalless Champions League draw with CFR Cluj.
The Ivory Coast striker left the stadium on crutches following a trip to a Romanian hospital after being stretchered off in the 58th minute of the match.
Drogba has only just returned from a knee problem which forced him to miss the opening weeks of the new season and his likely lengthy absence has left manager Luiz Felipe Scolari with an injury pile-up ahead of Sunday's Premier League game with Aston Villa.
Scolari was already without Michael Essien, Deco, Ricardo Carvalho and Joe Cole through injury.
But his problems have been compounded as Ashley Cole did not play against CFR Cluj with lower back pain, while central defenders John Terry and Alex both suffered knocks.
"I know nothing about Drogba, I just came into the room and he is with the doctor," said Scolari.
"Alex said he has a problem and can't move, John Terry is (hurt) in the back.
"Ashley felt his back before yesterday and it was impossible to play. For Sunday, he is ready.
"I have a few days to build the team again. One player is better than another for the game Sunday.
"I don't know now what the possibilities I have for Sunday are, maybe after tomorrow I have a chance to say something more."
Speaking about the performance in the goalless draw, he added: "I am happy with all of my players, they tried.
"We had some injuries, the pitch was normal, not bad, but some injuries came during training and during the game.
"Injuries come sometimes and we need to inspect this as we play."