Prop Rupert Harden is expected to miss the rest of Gloucester's season and could require surgery.
The Australian-born tight-head damaged knee ligaments in the his side's 31-25 defeat by Bath on 1 March.
Gloucester director of rugby Nigel Davies told BBC Gloucestershire: "Rupert probably will be out for a while - we're still assessing that.
"We have to adapt and react to that. We've got players who can step up and who have done all year."