Dragons hooker Rhys Thomas has been ruled out until next year after suffering an ankle injury.
The 30-year-old was injured in the early stages of the Dragons' 23-16 win against the Scarlets at Rodney Parade.
The former Wales front-rower, who joined the Dragons from Wasps during the summer, will be sidelined for three months, though he will not require an operation on the injury.
"It's a shame because Rhys was playing well and he was enjoying his rugby here," said Dragons director of rugby Lyn Jones.
"He is one of those experienced characters that adds a lot on the pitch and on the training field as well.
"It is a blow but it's not the end of the world and he'll be surprised by how quickly the three months goes."
Hugh Gustafson is poised to replace Thomas in the Dragons side to face Munster on Saturday with Sam Parry, who was called up to the Wales training squad last summer, on the bench.