Richard Dunne is a fitness doubt for Aston Villa ahead of their midweek showdown with Sunderland.
The centre-half picked up an Achilles problem during Saturday's 2-2 derby day draw with Wolves.
He now faces a race against time to shake off the complaint in time to prolong his ever-present record in the Premier League.
Villa's medical team will do all they can to get Dunne right for the home date with Sunderland, but Martin O'Neill accepts a gruelling schedule was always going to take its toll on his players.
"He did well to come out for the second half (against Wolves) because he has got an Achilles problem," O'Neill said in the Birmingham Mail.
"He was very sore at half-time but we'll monitor it and see how it goes. Is it the number of games catching up? I think it is a combination of those things."
While Dunne faces an anxious wait before finding out whether or not he will be given the all clear to face the Black Cats, John Carew is guaranteed to be involved.
The Norwegian took his tally for the season to 13 with a brace at the weekend and O'Neill admits the burly frontman could be vital to Villa's hopes of securing European qualification this term.
"I'm absolutely delighted that he is coming into good form at the moment," he added.
"He seems to be clear of the little niggles that have affected him this year and I just hope he can stay fit between now and the end of the season because we'll need him and we'll need everybody.
"I'm really pleased. You've got to get in there, you've got to score them and he did that on both occasions."