Reds wing Lachie Turner will be sidelined for five weeks after undergoing surgery to clean up loose cartilage in his ankle on Tuesday.
A regular starter with the Reds in 2014, Turner missed last weekend's match against the Western Force due to the ankle complaint.
He is expected to be available for selection in time for the Reds' home clash with the Rebels in Round 14.
Reds head coach Richard Graham said the absence of Turner's experience in the back three would be a loss for the team.
"It is disappointing to lose Lachie (Turner)," he told the Reds' official website.
"e has been playing very well and has offered some versatility among the back three.
"He suffered a fracture and dislocation of his ankle in early 2013. Unfortunately some cartilage has come loose in the same ankle and is irritating the joint."
Turner joins several other Reds in rehabilitation, including Liam Gill (hamstring-five weeks), Ben Daley (knee-two weeks), Samu Kerevi (ankle-two weeks), Chris Kuridrani (ankle-five weeks), Dom Shipperley (hip flexor-two weeks) and Aidan Toua (pectoral-12 weeks).
"We have a few boys out with injury at the moment but we are fortunate to have Chris (Feauai-Sautia) and Saia (Fainga'a) returning from injury and available for selection this week," added Graham.
"We've obviously still got some depth within our squad, with a lot of the younger group having been exposed to the Reds A program."