Ireland pair Jamie Heaslip and Rob Kearney have seen their hopes of British and Irish Lions selection placed in doubt after undergoing minor surgery that will result in significant lay-offs.
Heaslip has completed a back procedure that rules him out for an unspecified number of weeks while Kearney has had surgery on a knee issue requiring four to six weeks of rehabilitation.
Neither player was able to take part in the final match of the RBS 6 Nations against England last Saturday, with Heaslip withdrawing from the team shortly before kick-off and Kearney sidelined earlier in the build-up.
"It's hard to be definitive with timelines. Jamie just had a procedure done on his back. He had disc issues. Obviously they come on quite quickly," Leinster boss Leo Cullen said.
"It obviously rules him out of the next number of weeks. When we get a report we'll find out how long that will be. It sounds like they're reasonably standard procedures.
"Rob had an issue with his knee. It happened early during training in the week of the the England game.
"He had a procedure done during the week after seeing a specialist on Tuesday. That's probably four to six weeks. We'll see how he comes through that."
Both players have been involved in the last two Lions tours but face contrasting prospects of travelling to New Zealand this summer.
Heaslip, the number eight, is likely to be squeezed out of contention by Billy Vunipola and Toby Faletau but Kearney has a good chance of being picked as one of the full-backs when the squad is named on April 19.