Captain Stiliyan Petrov is a worry for Aston Villa ahead of their crunch weekend home game against top-four chasing Chelsea.
The West Midlands side are low on confidence following last weekend's 3-0 defeat by Arsenal and are in danger of slipping into the relegation tussle.
Although the club are currently eight points clear of the bottom three, Alex McLeish's side face a tough run of fixtures in April after the Blues' visit to Villa Park.
Alan Hutton and Charles N'Zogbia will almost certainly miss the game with respective calf and knee problems while Darren Bent (ankle), Richard Dunne (collarbone) and Ciaran Clark (knee) are sidelined.
And with James Collins and Emile Heskey carrying knocks, there is now a real worry over the Bulgarian.
"Stan Petrov's got a bit of a fever," explained assistant manager Peter Grant.
"He came off after the game with a high temperature on Saturday.
"He didn't feel that great during the game. The doc took his temperature on the way back up and it was very high."
French winger N'Zogbia has knee ligament damage and is facing a month out of action, although Grant remains puzzled by the way he picked up the injury following an accidental collision with Gary Gardner in training.
"It's so strange the way he got the injury," said Grant.
"It flared up and we knew it was more serious, although the boy was saying he thought it was just a bit of a knock. We thought the way he's actually blocked it, it could be a medial ligament and it was.
"We'll get more of a word on that soon because he was going to see the guy Tuesday afternoon.
"The doc will know more and then we'll get him back over and hopefully start getting him back on his feet again."