Ireland out-half Joey Carbery will miss the Six Nations due to the injury he sustained against Ulster last week.
Munster head coach Johann van Graan confirmed today that the the 24-year-old would be out for between two and four months following surgery on damaged ligaments in his wrist.
Carbery had only recently returned to provincial action following the ankle injury that hampered him during the World Cup.
"That's rugby, I'm gutted for Joey as an individual," said Van Graan.
"He worked hard to get back into the position, he played the full 80 for the first time for quite a while and now he is out for a considerable amount of time.
"That's rugby, that's life. He'll be back, he's a class man and a brilliant rugby player.
"He'll come back stronger, take his time and I can't wait to have him back in the future."
Confirmation of Carbery's absence means Ireland head coach Andy Farrell could be without both his first-choice No 10s for the tournament opener against Scotland on 1 February as Johnny Sexton is currently recovering from a knee injury.
Munster are also facing a crisis in the position for Sunday's crucial Champions Cup tie against Racing 92 in Paris.
Tyler Bleyendaal is out with a neck injury leaving JJ Hanrahan, who is "50-50" with a hamstring problem, as the only experienced out-half.
If Hanrahan isn't fit then 20-year-old Ben Healy or centre Rory Scannell will have to step in.
"JJ did a bit of the team training and the true test will be on Friday. If he comes through he'll play on the weekend," said van Graan.
"I'd say 50/50 is a good way to put it. He is an experienced No 10, he knows the team needs him for possibly 80 minutes so he needs to be at 100% to perform.
"I won't risk him if the medical team says he's not 100% right. Hopefully he makes it, but if he doesn't then we've been in this position before and we back the next man in.
"Ben has grown quite a lot over the last few weeks - he's been part of game-day warm-ups, he's been part of the squad and Rory has trained there."
Winger Andrew Conway (neck) and full-back Mike Haley will both also face fitness tests on Friday ahead of what is a must-win game for Munster.
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