The Irish fly-half was removed from the field last weekend’s 35-24 defeat to Connacht - which ended a 26-game unbeaten run in the competition - but he has recovered in time for this must-win matchup.

The reigning PRO14 champions face a formidable Ulster unit that has won all ten of its domestic fixtures this season - although they are yet to win in Europe.

They make six changes from the side that defeated Munster 15-10 last time out – with Jacob Stockdale missing out due to a knee injury.

Munster themselves welcome back 10 internationals ahead of their PRO14 fixture against Connacht tomorrow – including front row James Cronin who makes his 100th domestic appearance for the province.

Conor Murray and JJ Hanrahan renew their partnership in the backfield - the latter leads the Heineken Champions Cup in points scored with 30.

Connacht themselves make four changes to the side that defeated Leinster – Finlay Bealham, Ultan Dillane, Sean O’Brien and Ben O’Donnell all named by Andy Friend.

In the Gallagher Premiership there is a battle of the European champions as the Exeter Chiefs host Bristol Bears on Saturday afternoon.

Chiefs have named a strong XV which includes EPCR European Player of the Year Sam Simmonds after a defeat last time out against Wasps.

Internationals Luke Cowan-Dickie, Harry Williams, Jonny Hill and Henry Slade all return for the reigning Premiership champions.

European Rugby Challenge Cup winners Bristol Bears have announced a near full-strength 23 to take on the Chiefs – Semi Radradra lining up on the wing with back row Steven Luatua captaining the side.

Leinster Rugby captain Johnny Sexton returns to the starting XV for four-time Heineken Champions Cup winners tonight when they face off against Ulster Rugby in a crucial Guinness PRO14 clash