Wales centre Gavin Henson faces a scan on an ankle injury picked up during Ospreys' 17-0 EDF Energy Cup semi-final defeat to Gloucester.
The 27-year-old visited a specialist on Monday after being forced off before half-time on Saturday.
However Ospreys have been boosted ahead of their Heineken Cup quarter-final showdown with defending champions Munster on April 12 by the news Wales lock Ian Gough will be fit despite suffering a hip injury against Gloucester.
Full-back Lee Byrne already faces a race against time to be fit for that last eight clash and Ospreys will certainly be without long-term injury victims lock Ian Evans, prop Duncan Jones and Scotland winger Nikki Walker.
Henson had to be replaced by Jonathan Spratt shortly before the interval while Gough's injury forced him off the park after only 26 minutes.
Ospreys physio Chris Towers said: "Ian Gough suffered a haematoma in his hip region.
"Although the injury is low in severity, it is quite limiting in the short term. However, he will make a full recovery in time to face Munster in the Heineken Cup.
"Gavin Henson met with a specialist and had an MRI scan on Monday and we are now awaiting a formal report and feedback on his condition and prognosis.
"We will be fully informed as to the extent of his injury in the next 24 hours and will issue a further update accordingly."
Ospreys boss Sean Holley said Henson's new injury was not a recurrence of the calf and ankle problems he has already suffered this season.
"It's the other foot," said Holley. "It looks like a bit of an ankle injury.
"We've got quite an extensive injury list now to contend with."
England flanker James Haskell insists he will be pushing as hard as possible to be back from a toe injury in time to make his case for a spot in Eddie Jones' side looking to defend their RBS 6 Nations title next year.