Bath and England hooker Lee Mears is set to be sidelined for at least eight weeks with a bicep injury.
Director of rugby Sir Ian McGeechan confirmed to BBC Radio Bristol that the 32-year-old had ripped the muscle from the bone in training last week.
He missed Sunday's Heineken Cup defeat by Glasgow and has been deregistered for the rest of the pool games, which run until the end of January.
Mark Lilley will take his place in the squad for the cup competition.
Mears has only recently returned to the Bath set-up after spending time on World Cup duty in New Zealand, where he made one appearance against Romania.
His injury could have implications at international level with the England elite squad set to be announced in early January.