Gloucester winger Ollie Thorley will miss the rest of the season due to a knee injury suffered during their game against Northampton last month.
Number eight Zach Mercer is also set for an unknown spell on the sidelines due to a knee injury which requires surgery.
Thorley, 28, went off after 19 minutes in the win away to Saints on 30 November, with Mercer also going off late on.
“It’s a nasty one and he’s been playing really well and he’s a really key part of what we do,” director of rugby George Skivington told BBC Radio Gloucestershire.
“He’s a great bloke – Gloucester through-and-through. It’s an innocuous one, doesn’t seem too much in it and he was pretty buoyant after the game so I didn’t think it was too bad.
“It’s one of those where you have to do the rehab and come back fitter and stronger but unfortunately for this season that’s Ollie done.”
Mercer has played almost every minute of Gloucester’s seven Premiership matches so far this season as their starting number eight, going off in the closing stages at Franklin’s Gardens after scoring a try in the 25-17 win.
Skivington said the 27-year-old’s injury is “not good news”.
“Zach’s is a little bit more complicated so I’m not sure the exact timeline, but there is surgery involved in it, it’s not good news whatever it is,” Skivington said.
“But we’ll wait and see. I couldn’t give you an exact timeline involved in that but it’s not positive.”
