Will Collier and Nick Evans are both out of action for several weeks for Harlequins after picking up injuries in the 29-26 victory over Sale last weekend.
Tighthead Collier sustained a broken ankle and is expected to be out for eight weeks while Evans who was forced off with a concussion also suffered a fractured wrist.
Harlequins director of rugby John Kingston confirmed that Evans would not need an operation and is expected to return some time in the middle of February.
The injury to Collier is just another in a long list of front row injuries for Harlequins, Joe Marler is out for 4-5 weeks with a fractured leg while Mark Lambert won’t return until mid-February and Cameron Hollenstein is expected back just before the end of the season.
In the second row James Horwill is expected to return for next weekend’s game with Stade Francais while Sam Twomey, who has a long-term foot injury, has a meeting next week to determine the speed of his recovery.
Former England captain Chris Robshaw is recovering from shoulder surgery and is due back at the end of March.
In the backs Harry Sloan has been ruled out for the rest of the season by Kingston while George Lowe should return in six weeks following his back injury.
Ross Chisholm and James Lang are anticipated to return to action in the next rounds of the Anglo-Welsh Cup should their rehabilitation progress as expected.