Paul O'Connell is a major concern for Ireland's tour to New Zealand next month after suffering a serious knee injury against Ulster at Thomond Park.
The lock has been ruled out for four to six weeks because of the damage he sustained during Saturday night's 36-8 Pro12 win over Ulster.
O'Connell is ruled out of Munster's Pro12 semi-final against the Ospreys on Friday night, along with Damien Varley.
Ronan O'Gara has resumed training and is in contention for that game.
O'Connell was helped from the field after 55 minutes of the match against Ulster.
He suffered damage to the same knee he injured against France, which cut short his Six Nations campaign earlier this season.
He returned in time for the Heineken Cup quarter-final defeat to Ulster.
"It's the same knee, but the injury he had before was more of a cut - this is more of a twist, so we will have to wait and see," said coach Tony McGahan.