Bath winger Joe Cokanasiga faces a lengthy spell on the sidelines after returning from England's World Cup campaign with a serious knee injury.
The 22-year-old only featured once for Eddie Jones' side in Japan.
Cokanasiga started the pool stage win over the United States, scoring two tries as he played the full match.
A statement on Bath's website said Cokanasiga's injury "will result in him being unable to begin a competitive campaign for the club".
Cokanasiga has won nine caps since making his England debut against Japan in November 2018.
"We must manage him very carefully in the coming months to allow for the issues he has come back from Japan with to begin to be resolved," Bath director of rugby Stuart Hooper said.
The Premiership club's medical department are "enlisting the services of world-leading specialists" in order to "deliver an optimal pathway to recovery".
Meanwhile, prop Henry Thomas will miss the rest of the season with an anterior cruciate ligament injury he suffered against Wasps earlier this month.
Back row Zach Mercer is also set to see a specialist to determine the extent of the knee injury he sustained in the Champions Cup defeat by Ulster on Saturday.