Munster will be without Damien De Allende for a number of weeks, while Niall Scannell will miss Sunday's visit of Wasps.
The province confirmed the twin injury blows ahead of Sunday's decisive Pool B game in the Heineken Champions Cup.
Springbok centre De Allende is being managed for an abdominal injury and will be unavailable, they say, for a number of weeks.
Meanwhile, hooker Scannell will be sent for a scan on a shoulder injury picked up during Friday night's dramatic win away to Castres.
Gavin Coombes' late, late try maintained Munster's 100 per cent record in their Champions Cup pool, ahead of Sunday's game at Thomond Park.
A win on Sunday will not only secure Johann van Graan's side a home last-16 tie, but also a quarter-final at Thomond Park should they progress that far.
"We’ve put ourselves in a really good space," he said after Friday's game, "So it’s a massive game for us against Wasps next Sunday.”
There is good news for the head coach, with three players back in contention for Wasps after various injuries.
Calvin Nash (ankle), Jason Jenkins (abdomen) and Chris Cloete (neck) will all resume training this week, and will be assessed ahead of Sunday's game.
Meanwhile, Bradley Roberts' return to fitness at Ulster has seen Declan Moore's loan there cut short, and he has returned to Munster.