Richardt Strauss has been ruled out of Ireland's Six Nations squad with an ankle ligament injury.

The Leinster hooker picked up the injury in Saturday’s Heineken Cup victory over Exeter, having only returned from an ankle injury for the must-win encounter.

Strauss, however, only lasted the first half of the game at Sandy Park and was replaced by Sean Cronin.

The ankle ligament injury is expected to rule Strauss out of action for 10-12 weeks, which effectively rules him out of the entire championship.

And Ireland coach Decan Kidney has added seven players to the Six Nations extended training squad following the Heineken Cup games at the weekend.

Five Munster players, James Coughlan, Tommy O'Donnell, Mike Sherry, Damien Varley and Ian Keatley, will join Leinster pair Rhys Ruddock and Kevin McLaughlin at squad training at Carton House ahead of the opening game of the RBS 6 Nations against Wales on 2 February and the Wolfhounds’ clash against the Saxons this Friday.

Ulster's Roger Wilson was considered for inclusion but has been ruled out with a hamstring injury.

The Wolfhounds squad will be announced tomorrow with the team confirmed later in the week.