Millwall defender Danny Shittu could be facing a lengthy spell on the sidelines.
The experienced centre-half suffered an Achilles injury against Derby at the weekend which ruled him out of Tuesday night's 1-0 defeat at Blackpool.
Shittu is due to visit a specialist to determine the extent of the problem, but Lions boss Ian Holloway fears the worse.
"Danny might have a more serious problem," said Holloway.
"He's got a nick in his Achilles and will have to get it assessed by a specialist, but that doesn't look good at the moment."
The news comes as a blow to Millwall ahead of a relegation six-pointer against derby rivals Charlton on Saturday.