England centre Henry Slade faces a long spell on the sidelines after injuring both his ankles playing for club side Exeter Chiefs in the Premiership last weekend.
The 26-year-old limped off the pitch in the opening half of Exeter's 31-22 victory over Leicester Tigers on Saturday and the injury to his right ankle is more serious than the initial one to his left.
"Sladey's going to be out for a little while. He's picked up injuries to both of his ankles. He tried hobbling along with one, until he picked up the second," said Exeter director of rugby Rob Baxter.
"The second injury is more of a concern as it's an injury in around an old injury, which he had had previously plated. Right now, he's continually being assessed and we'll know more in due course.
"It is, however, nothing something he'll be able to get over in a week or two, it's more significant than that."
Slade faces a race to be fit for selection ahead of the Six Nations next year with England beginning their campaign against France in Paris on February 2.
England head coach Eddie Jones could also be without Wasps flanker Brad Shields, who has injured the same foot that ruled him out of the World Cup squad.