Last year’s Super Bowl Most Valuable Player was hurt on a running play in Sunday’s game.
Luckless Munster out-half needs surgery for the injury.
The tighthead prop suffered ankle ligament damage in his side’s win over Edinburgh.
Sam Underhill suffered ankle ligament damage in Bath’s Premiership win over Leicester Tigers at the weekend.
The Ireland head coach is confident all three will be fit and available for selection next week.
Ramsey injured his hamstring in the win against Bayern Munich.
Luke Marshall is back in training however.
Brian O’Driscoll sat out this morning’s training session but is expected to be back in training by Wednesday.
Munster coach refuses to rule out the possibility of his captain appearing against Harlequins.