Seán O’Brien may miss rest of the season

Ireland and Leinster have been dealt a potentially crippling blow by the news that Seán O'Brien will miss the Six Nations championship and possibly the rest of the season with a dislocated shoulder.

The Carlow man sustained the injury in the 19-6 win over Ulster at the RDS on Saturday and will undergo surgery this week. The fact a procedure is necessary would suggest his entire season is in jeopardy, with a five-month convalescence the usual forecast, and after initially suggesting a six to eight week lay-off this afternoon, Leinster revised it up to "several months".

“Otherwise, apart from a few minor knocks, the squad trained as normal ahead of Friday’s midday team announcement (for the game against Connacht on Saturday),” a statement added.

Earlier, at a press briefing, forwards coach Jono Gibbes said the fact the injury “is significant enough for surgical intervention ... means six to eight weeks minimum.

He added: “It looks like that (he will miss the entire Six Nations), but they are not going to put an absolute line in the sand for him. They are just going to see how it goes.”

O'Brien has started just seven games this season, and only five of those with Leinster, but that could now be it for this year, for a player currently planning his next big contract with the IRFU or wealthier suitors further afield.

The Six Nations opener against Scotland is just five weeks away and, as it stands, Ireland will take to the field at the Aviva Stadium without two of their biggest hitters, in the shape of O'Brien and prop Cian Healy, ruled out of the first two games at least with an ankle injury.