London Wasps flanker James Haskell will be out until the beginning of October after undergoing knee surgery.
Haskell is continuing his rehab from a knee procedure underwent earlier in the off-season and is making good progress, though he is likely to miss the first few games of the season, with a return likely in October.
Wasps have also released details of other fitness concerns in their squad ahead of a pre-season camp in France.
James Bailey is continuing his rehab from a serious leg operation last year.
Elliot Daly is making good progress on his recovery from an operation on a broken metatarsal. He is on course for a return to play within 8 weeks.
Ashley Johnson (hamstring), Joe Launchbury (neck and shoulder) and Hugo Southwell (hamstring) are receiving treatment on various niggles.
While their involvement in pre-season games is expected to be minimal, they are all expected to be fit for the opening competitive game of the season.