Merriman's Achilles flared up during Thursday's practice, and he was held out of Friday's practice altogether. He did not make the trip to MetLife Stadum.
Merriman said Friday he didn't think the injury was significant. The Bills will have their bye next week, giving him an additional week to heal.
Merriman finished last season on injured reserve because of a nagging injury to his right tendon.
With both Merriman and Chris Kelsay (calf) out, the Bills will be down to two healthy outside linebackers -- Danny Batten and Arthur Moats. Defensive lineman Spencer Johnson will also be available to fill in after working with the outside linebackers on Friday.
Linebacker Nick Barnett (ankle) said Sunday he will play despite being listed as questionable.
Information from The Associated Press was used in this report.