Wales prop Adam Jones is unlikely to play again before Christmas, ruling him out of the Ospreys' crucial Heineken Cup double-header against Toulouse next month.
Jones was ruled out of Wales' current autumn Test campaign due to a knee injury and it is the second major injury blow for the Ospreys in 24 hours.
Skipper Alun Wyn Jones was ruled out for up to four months after injuring his shoulder against Argentina last week.
Ospreys physiotherapist Chris Towers said: "Although Adam remains unavailable due to the knee injury he re-aggravated in the Leicester match (last month), we are happy with the progress he is making in his rehab.
"In line with the initial rehab plan, he still requires a further six weeks to get him back to the condition required to reach a position where he will be able to return to playing."