The Patriots will host the Colts at Gillette Stadium Sunday evening, and losing Nixon gives the Colts only two healthy offensive tackles, Anthony Castonzo and Joe Reitz.
The Colts will also be without running back Trent Richardson, who did not travel with the team due to personal reasons. Linebacker Josh McNary was also placed on the commissioner's exempt list on Thursday after McNary was charged with rape.
Neither Nixon nor Richardson was going to dress for Sunday's game, according to Bob Kravitz of WTHR.com.
The Patriots finished 12-4 and have lost in the conference finals the past two seasons.
- Mike Fiammetta