The Munster lock - a key member of Irelands pack - sustained the damage in the dramatic 19-13 triumph at Twickenham two weeks ago but was expected to be fit for the clash at Lansdowne Road.

Coach Eddie OSullivan said: Paul was on course to make the match but this morning he just wasnt right. We werent worried about it earlier this week but ribs can be notoriously slow to heal. He should be fine for next weekend.

Donncha OCallaghan moves off the bench to plug the gap - he joins Malcolm OKelly in the second row - while Ulster forward Gary Longwell is handed OCallaghans place among the substitutes.

Although a quality operator, OCallaghan has only recently shaken off the knee injury which forced him to sit out the victory against England - and his Munster team-mate OConnell is a tough act to follow.

OConnells performances during the World Cup catapulted him into many observers tournament XV and he has followed his form in Australia with more of the same in this years RBS 6 Nations.