Millwall winger Chris Taylor needs a scan on a groin injury.
Taylor limped off after half an hour of Tuesday night's 1-0 win over Watford and the Lions are waiting to discover the extent of the problem.
"He's been struggling with his groin now for a few weeks," revealed assistant-boss Joe Gallen.
"Full credit to him, he's played through it but before the game there were question marks about it.
"He declared himself fit and he's been doing very well, but unfortunately within half an hour it flared up again.
"So it will be a scan, and then a decision."