Leicester Tigers have confirmed that Mike Williams faces a spell on the sidelines after breaking his arm in the Premiership game at his former club Worcester Warriors.
Tigers director of rugby Richard Cockerill said he was "bitterly disappointed" for the 24-year-old, who has become a hit with supporters since his arrival at Welford Road.
"Mike Williams had surgery on his arm on Sunday, he's had a plate put in and he will be out for possibly three months," said Cockerill.
"He has been great. He's a good bloke and has played very well for us.
"Even in the game, he made the tackle and broke his arm, but he gets back into the defensive line and makes the next tackle. I don't know whether that's daft or brave – or a bit of both!
"His attitude has been great. He has played really well and we're bitterly disappointed for him that he's now out with an injury."
Niall Morris continues to progress as he returns from the ankle injury he sustained at The Rec in last season's Premiership semi-final, and Cockerill confirmed that Manu Tuilagi is being reintegrated into rugby as he comes back from long-term injury.
Meanwhile, Leonardo Ghiraldini (groin), Opeti Fonua (arm), Logovi'I Mulipola (knee) and Jean de Villiers (jaw) are also progressing well in their return from injury.