Ospreys wing Jeff Hassler will miss the final three games of the season after undergoing shoulder surgery.
The 24-year-old Canada international is expected to be fit in time for pre-season training in the summer.
Ospreys medic Chris Towers said Hassler had been carrying the injury since October.
"Jeff's had an ongoing shoulder problem that we've had to manage since his return from the Rugby World Cup," he said.
Ospreys are fighting to gain European qualification with three matches left in the Pro12 against Treviso, Cardiff Blues and Ulster.
"In light of him being unavailable this weekend anyway due to a short term soft tissue injury we have elected to repair the shoulder through surgery, giving him the maximum recovery time and the best preparation for next season," added Towers.
On Monday, the Swansea-based region confirmed flanker Justin Tipuric, prop Paul James, centre JJ Englebrecht and prop Ma'afu Fia were all out for the season.