League sources told ESPN and NFL Media that Edelman underwent a precautionary knee procedure Thursday morning. According to ESPN, he is expected to be sidelined for "some period of time" because of the knee ailment, which has limited him all season.
The 34-year-old Edelman practiced on a limited basis Wednesday, but the team listed him as a non-participant in Thursday's practice.
Edelman leads the Patriots in receptions (21), receiving yards (315), targets (39) and yards per reception (15) this season.
The Patriots also could be without second-year wideout N'Keal Harry on Sunday. He remains sidelined because of a concussion.
If Harry is unable to suit up against the Bills, the Patriots would have only Damiere Byrd, Jakobi Meyers and Gunner Olszewski at receiver.
The Patriots (2-4) travel to play the Bills (5-2) at 1 p.m. EST Sunday at Bills Stadium.