Warriors pair Duncan Weir and Sam Lewis will be both be sidelined for around 12 weeks with shoulder injuries that will require surgery.
Both sustained the injuries against Leicester Tigers two weeks ago with Scotland international fly-half Weir suffering a grade three tear in his acromioclavicular joint and openside flanker Lewis a grade four tear in his same joint.
Warriors hope that fly-half Billy Searle will return to action within two to three weeks having missed the Gallagher Premiership matches against Leicester and Wasps because of a gashed thigh muscle which he sustained against Exeter Chiefs three weeks ago.
Hooker Matt Moulds is on course for a return to action in the middle of next month after almost a year out with a foot injury.
Moulds underwent surgery to repair and stabilise an existing injury last summer but further complications have delayed his comeback.
Francois Hougaard and Anton Bresler are also back in full training.