Tyler Bleyendaal and Jeremy Loughman will miss Munster's Champions Cup clash with Saracens on Saturday.
Munster's out-half options remain depleted as Bleyendaal has been ruled out for several weeks.
Bleyendaal, who has undergone two neck surgeries since 2014, presented with neck stiffness after starting against Ospreys and will be out for "a number of weeks to rest in taking every precaution with his recovery".
However, Joey Carbery is progressing well in rehabbing his ankle injury, the province reports, and is set to make a return to play towards the end of this month. He has missed all provincial action since his return from the World Cup.
That means JJ Hanrahan is set to continue at number 10 for the back-to-back Saracens games. Academy player Ben Healy, who made his Munster debut last Friday in the PRO14, is an option should head coach Johann van Graan decide to draft another specialist out-half into the matchday squad, although centre Rory Scannell has provided back-up in recent games.
Loughman, who started Munster's opening two Pool 4 games, scoring a try against Ospreys, won't require surgery on his ankle. He suffered the injury against Racing 92 and his recovery will be "managed conservatively".
His fellow loosehead prop Dave Kilcoyne remains out with a calf injury, so James Cronin is the leading contender to get the start against the reigning European champions.
Chris Cloete, who suffered a head injury against Ulster last month, continues to follow the return to play protocols.
Winger Darren Sweetnam (hamstring) and tighthead prop Ciaran Parker (calf) also remain unavailable.