Worcester flanker Sam Lewis has been ruled out for the rest of the season.
The 25-year-old Welsh back row forward has been told that he needs surgery on the troublesome shoulder injury that has kept him out all season.
Lewis suffered nerve damage after being injured in the Warriors' pre-season friendly at Northampton Saints.
"We've tried a fairly conservative approach, but the problem hasn't had a sufficient response," said Warriors director of rugby Dean Ryan.
"The medical team are now looking at surgical intervention. It stems from having a shoulder impact injury. He will require surgery to try to stimulate a nerve and that will rule him out for the rest of the year."
After arriving at Sixways from Ospreys in March 2015, Lewis has made just five Warriors appearances, scoring four tries, including a hat-trick in the second leg of their Championship play-off semi-final win over London Scottish.
Up next for Ryan's Warriors
Worcester face a key fixture in the four-team fight to avoid the drop to the Championship on Friday, when they head to Kingston Park to face Newcastle.
Dean Ryan's side face a Falcons side that have won their last four Premiership home games on their artificial pitch.
"It's clearly creating problems for a lot of teams," Ryan told BBC Hereford & Worcester. "They've had a decent run of results there."
Since losing 38-3 to Saracens there before Christmas, after which they signed vastly experienced ex-Worcester and England stand-off Andy Goode, Newcastle have beaten Bath, Harlequins, Leicester and Northampton to rise to 10th.
That has put them three points behind ninth-placed Bath and two points clear of Worcester, who are five clear of bottom club London Irish.
"We played pretty well for 40 to 50 minutes but it wasn't good enough to get a result," he added. "They're all important games now. We've got to get wins."
Young Warriors at Kingston Park
Four of Worcester Warriors' young Academy players got a close-up look at the Kingston Park pitch last Friday night, having played in England Under-20 26-20 defeat by Ireland.
Open side flanker Sam Ripper-Smith, who scored the first of England's two tries, hooker Jack Singleton and lock forward Huw Taylor all started, while scum-half Jamie Shillcock was on the bench.