Brad Barritt's chances of an England recall will be determined by an injury scan on Monday.
The Saracens centre was injured during their 26-17 Aviva Premiership victory over Wasps on Sunday.
Barritt was believed to be close to earning a recall to replace Luther Burrell in the England squad.
"We are all hopeful that it won't be too serious. It didn't look very good," Saracens head coach Mark McCall told Sky Sports News.
"Brad has been so unlucky this season and I am sure he would have been very close to selection for England next weekend. Fingers crossed it is not as bad as it looked."
England take on Scotland at Twickenham on Saturday, and can still win the Six Nations.