Bath prop Beno Obano is facing a long spell on the sidelines after rupturing his anterior cruciate ligament in their defeat by Harlequins last week.
The club have not put a timescale on how long Obano will be out for.
Bath are bottom of the Premiership having lost all five of their matches so far this season.
"This is a complex injury that takes time to recover - we will provide a huge amount of care for Beno to ensure his safe return to the field," director of rugby Stuart Hooper told the club website.
"His professionalism to overcome serious injuries in his career to date has been remarkable and I know this instance will be no different."