Luke Fitzgerald is set to miss Ireland's Six Nations campaign after suffering suspected medial ligament damage in his left knee during Friday's open training session at the Aviva Stadium.
The Leinster back was helped from the field during the session and a scan is expected to confirm the bad news. Fitzgerald is expected to be out for between six and eight weeks
The IRFU will confirm Fitzgerald’s absence in their next medical update, with the squad set to return to Carton House on Tuesday ahead of the opening game against Wales in Dublin the following Sunday.
There was good news for Ireland coach Joe Schmidt as Rob Henshaw came through Connacht's victory over the Scarlets in Galway on Saturday, while Jared Payne has also returned to action in recent weeks.
There was further good news for Ireland midfielders, with Stuart Olding making a try-scoring return to action in Ulster's bonus-point win over Treviso in Italy.
Olding has been out of action since March after suffering an anterior cruciate injury and was partnered with fellow Ireland international Darren Cave.
Cave also went over for a try, with Ulster coach Les Kiss impressed with Olding's return, which included playing the final quarter at outhalf.
“Stuart is such a great player and you can see that in the way he understands the perfect timing and space,” said Kiss.
“ In the last 20 minutes I asked him to play at number 10 giving him a bit more exposure and he came out of it brilliantly. He’s just a class and extraordinary guy,” added Kiss.