Scarlets forward Morgan Allen has been ruled out of action for 16 weeks with a ruptured biceps.
The 25-year-old suffered the injury during a training session on Tuesday before undergoing surgery on Wednesday.
Allen joined the Scarlets in May following a four-year spell with Ospreys.
"Morgan's surgery went well on Thursday and he will start his rehabilitation next week once his cast is removed with a progressive loading program," medical chief Andrew Walker told the club's official website.
Allen has represented Wales at Under-18 and Under-20 levels.