The Irish heavyweights, four-time tournament winners, will face holders Bordeaux-Begles or Premiership champions Bath in the final on May 23rd.

However, Tadhg Furlong has not recovered in time for the game, with Thomas Clarkson starting on the other side of the scrum.

In one of the biggest success stories in Irish rugby in the last two seasons, O'Brien has played his way into Leinster and Ireland's starting 15.

Winger Jordan Larmour and second-row Diarmuid Mangan have also returned to training following long-term injuries.

Munster slipped to a second Champions Cup defeat after going down 27-25 away to Toulon in pool two