Keith Earls has been ruled out of Munster's must-win Heineken Champions Cup clash with Ospreys this Sunday.
The Ireland winger suffered a minor knee injury in training while lock Jean Kleyn has been ruled out with a neck issue.
Calvin Nash makes his European debut on the wing, and Waterford's Jack O' Donoghue is named in the back row for the Red Army for this crunch encounter.
📢 TEAM ANNOUNCEMENT
Our side has been named for Sunday's #HeinekenChampionsCup clash against Ospreys at @ThomondStadium!@CalvinNash101 makes his Champions Cup debut with Academy duo Jack O'Sullivan and Ben Healy among the replacements. #MUNvOSP #SUAF 🔴 pic.twitter.com/km8vg78CeY— Munster Rugby (@Munsterrugby) January 17, 2020
Meanwhile, Will Addison has been passed fit to start at full-back for Ulster match against Bath tomorrow.
Having been named in Ireland's Six Nations squad this week, Tom O'Toole has been named in the front-row.
Victory for Dan McFarland's side would see them qualify for the quarter-finals.
James Ryan has skaken off his calf injury to start for already qualified Leinster in their game away to Benetton.
Max Deegan will start at blindside with Caelan Doris at number-eight.
Sean Cronin and Andrew Porter also come into the side.
Scrum-half Kieran Marmion will make his first appearance for Connacht in two months on Sunday.
He's back in the team for their final pool game away to Montpellier.
Neither team can qualify for the quarter-finals.
Elsewhere, Saracens could be automatically relegated from the English Premiership if they fail to meet the salary cap this season.
The defending champions have already been docked 35 points and fined 5-point-3 million pounds after they were found guilty of breaking rules over the last three campaigns.
Other clubs are demanding Saracens now prove they are within the 7 million pound limit for this year or face demotion to the Championship.
Saracens in hot water https://t.co/lQjLE36krQ #rterugby #rtesport
— RTÉ Sport (@RTEsport) January 17, 2020