Tom Varndell ruptured his bicep in training yesterday and a scan has revealed that the winger will need three to four months of recovery following an operation this week.
Rory Pitman, back row, suffered significant ankle ligament damage playing in an A league game on Monday night and he will also require surgery. He is also likely to be out for three to four months.
There is better news for captain Chris Bell, who is in in contention for the trip to Exeter this weekend, while lock Kearnan Myall is expected to be available for selection next weekend.
Hugo Southwell, James Bailey, James Haskell, Phil Swainston and Elliot Daly are unlikely to play in September but are making good progress on their respective injuries.