Highly-rated Saracens flanker Will Fraser will undergo an operation on Tuesday to resolve long-standing problems with his back.
The loose forward was being widely tipped for England selection a few months ago but will now miss the rest of the 2014/15 season.
“It’s obviously disappointing for Will and for us,” said Mark McCall, Director of Rugby.
“But it’s obviously in everybody’s interest to sort out these issues once and for all.
“Will is only 24, and he has plenty of great rugby in him, for club and country.”