Bath centre Jonathan Joseph has been ruled out for two months after picking up a leg injury in the Challenge Cup.
The England international, who has four caps, sustained the injury in last Thursday's comfortable victory over Bordeaux-Bègles, limping off after scoring a try.
The 22-year-old outside centre was on the fringes of England's squad for the Six Nations, but will now be out for the duration of the tournament.
Joseph joined Bath from London Irish this season and has been in fine form, scoring plenty of tries such as the one below against Harlequins.
Bath will now turn to one of Matt Banahan, Gavin Henson or Ben Williams to fill the gap at 13, with Horacio Agulla providing cover.
"It's a devastating blow," Bath coach Neal Hatley told BBC Radio Bristol.
"He's nearly been getting a try a game in the last few weeks and he's almost been the glue in our back line.
"But now it gives someone else the opportunity to come in."