Dave Kearney and Eoin Reddan are likely to miss the start of Ireland's Six Nations title defence after suffering injuries as Leinster squeaked through to the Champions Cup quarter-finals at Wasps.
Wasps rallied for a 20-20 draw with 14 points in the final quarter and now their hopes of reaching the last eight rest on results elsewhere across the weekend.
Wing Kearney picked up a "significant" shoulder problem after being upended while in mid-air by Wasps flanker Ashley Johnson, who received a yellow card for the challenge.
Scrum-half Reddan trudged off with knee ligament damage as Leinster blew a comfortable lead, and head coach Matt O'Connor admitted both Reddan and Kearney are doubts for Ireland's Six Nations opener in Italy on 7 February.
"Dave has got a bang on his shoulder. It's significant and he could be out for several weeks," O'Connor said. "Eoin Reddan has a medial strain on his knee."
Johnson was fortunate to escape a red card for upending the airborne Kearney after just 24 seconds of the match.
Leinster boss O'Connor acknowledged the Wasps flanker could easily have faced harsher punishment.
"The frustration for us is we lose a bloke for 80 minutes; they lose a bloke for 10 minutes," he said. "Now that doesn't make sense to me, but I haven't seen the incident again.
"I don't know whether it was right or wrong. A bloke takes a guy out illegally, and we lose a guy which compromises the bench, and they lose a bloke for 10 minutes.
"There is a duty of care on the player to make sure guys land safely."
Leinster's Ireland number eight Jamie Heaslip also came off in the second half, but O'Connor is confident he can carry the niggle into Six Nations action.
"Jamie's still carrying that shoulder. He was struggling a little so fresh legs were going to be important."