Ireland flanker Sean O'Brien is a doubt for the Six Nations after suffering a suspected dislocated shoulder for Leinster against Ulster.
O'Brien was forced off in the second half of Saturday's win at the RDS and looked in some discomfort.
Leinster head coach Matt O'Connor stated that O'Brien took a "significant bang", with the damage still be assessed.
A shoulder dislocation tends to require three months recovery time, with Ireland kicking off their Six Nations campaign against Scotland in only five weeks.
O'Brien has recently been the subject of plenty of speculation regarding his future with the Irish province, with a move overseas to the Top 14 on the cards.
Number eight Jordi Murphy scored Leinster's only try as they moved up to 2nd in the league after the 19-6 win, seven points behind Munster.