Exeter scrum-half Stuart Townsend is likely to miss the rest of the season.
The 23-year-old has what director of rugby Rob Baxter described as “a pretty serious knee injury”.
Townsend had been sharing scrum-half duties with Nic White after the Australian suffered a foot injury earlier this campaign.
White is currently out for a few weeks with a recurrence of the foot injury, so Jack Maunder is set to start against Saracens on Saturday if fit.