Knox (foot) has been ruled out for Sunday's game against the Steelers, Alaina Getzenberg of ESPN.com reports.
Knox's absence as the No. 1 tight end leaves Buffalo's already depleted receiving corps even more short-handed. Jamison Crowder (ankle) is set to miss time due to a fracture, and Isaiah McKenzie remains in the concussion protocol, while depth receiver Jake Kumerow (ankle) also is sidelined this weekend. For the tight end position, Quintin Morris and Tommy Sweeney will work to fill in for Knox.