Scott Dann looks likely to miss Birmingham City's Midlands derby against Aston Villa after tearing his hamstring, according to Blues manager Alex McLeish.
The 23-year-old centre back was touch-and-go ahead of Tuesday's Carling Cup semi-final first leg, but was passed a late fitness test.
However the Liverpool-born defender had to be withdrawn at the interval and could only watch on as his team were downed 2-1 thanks to 'keeper Ben Foster's blunder.
McLeish said it would be a big blow to lose the former Coventry man for Sunday's game at St Andrews against their bitter rivals.
McLeish said: 'We hope Scott isn't too bad but he has definitely torn ahamstring.
'He passed a fitness test on the morning of the cup game.
'Sometimes players want to play through even a wee niggle.
'Sometimes they get away with it but sometimes they can end up with a badinjury.'
Dann, who was playing non-league football four years ago, has formed aneffective partnership with Roger Johnson since making the move from HighfieldRoad during the summer of 2009.
Liam Ridgewell is likely to have to switch to play alongside Johnson againsthis former club on Sunday with David Murphy coming into the side at left-back.
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Explore more:People: Roger Johnson, David Murphy, Scott Dann, Ben Foster, Alex McLeish, Liam Ridgewell Places: Birmingham, Liverpool