Highly-rated prospect Luke Cowan-Dickie is expected to be on the sidelines until the end of January in a blow for Exeter Chiefs.
Exeter boss Rob Baxter revealed the news of Cowan-Dickie's setback on Monday.
Baxter told the BBC: "He's likely to be out for a couple of months while it heals.
"The way Luke plays, he does chuck himself around, and a few weeks off isn't going to do the rest of his body any harm."
Cowan-Dickie was one of four hookers included in England's preliminary World Cup squad earlier this year, although he missed out on making the final group of 31.