The winner of the Munster v Ulster Heineken Cup quarter final will have home country advantage in the semi final against the winner of the Edinburgh v Toulouse game.
The other semi final will see either Leinster or Cardiff Blues travel to either England or France to play the winner of the Saracens/Clermont quarter final.
Paul O'Connell is one of four Irish players named to start for the British and Irish Lions when they take on the Qantas Wallabies this Saturday in their first test.