Ian Evans has been ruled out of the rest of the Ospreys' 2012/13 Heineken Cup Pool stage action.
The Wales lock will be sidelined for up to eight weeks following an investigation into an ongoing knee injury.
Evans will miss the back-to-back contests against four-times champions Toulouse and January's Pool 2 fixtures at home to Leicester Tigers and away to Benetton Treviso.
He played in both of October's tournament matches and has appeared in 23 Heineken Cup fixtures since making his European debut in 2005 against Leicester Tigers.
"Ian has been troubled by an ongoing problem with his right knee since being unable to complete the Samoa game last month," said Ospreys Head Physio, Chris Towers.
"Investigations and consultations with specialists have resulted in him undergoing a keyhole procedure, as a result of which he will be sidelines for six to eight weeks."
