Gronkowski, coming back from multiple offseason surgeries on his left forearm and one on his back, returned to full-pads practices six days ago and had been limited all week. The Patriots had officially listed him as doubtful on the injury report.
It's also unlikely Gronkowski will be ready for the Patriots' second game, Thursday against the New York Jets, according to a source.
Without Gronkowski, the Patriots will enter Sunday's game with just two tight ends -- four-year veteran Michael Hoomanawanui and rookie Zach Sudfeld. That likely means the team won't run a majority of its plays out of multiple tight end packages, instead relying on three-receiver groupings, or tapping fullback James Develin in two-back sets.
Hoomanawanui (6-foot-4, 260 pounds) would project to more of an inline blocking role, while Sudfeld (6-7, 260) is more of a "move" tight end.
In addition to Gronkowski, the Patriots also declared rookie receiver Aaron Dobson [hamstring], running back Brandon Bolden [knee], offensive lineman Will Svitek [knee], and safeties Nate Ebner [ankle] and Duron Harmon [hamstring] to out for Sunday's game.