Conor McInerney is facing a spell on the sidelines after sustaining a knee injury during the game against Connacht.
The Irish second row was forced off at half time in the 16-15 win in Galway two weeks ago, and after struggling to shake it off has been ordered to rest by the Ospreys medical team.
Head Physio Chris Towers confirmed:
"Conor is having a period of enforced rest having failed to recover from the injury sustained against Connacht. He will have the knee scanned again in a couple of weeks time, after which we will be in a better position to gauge how best to treat the injury."