Sale forwards Sebastien Bruno and Sean Cox both picked up long-term injuries during the 28-6 defeat to London Irish.
Hooker Bruno ruptured his bicep and is expected to be out for at least four months, while lock Cox's dislocated kneecap will sideline him for between four and five months.
"This is bad news for both players and the club," said director of rugby Philippe Saint-Andre.
"Both Sebastien and Sean have been playing well and they will be missed.
"They will receive the best medical care and help with their rehabilitation and we look forward to having them back playing again."