Brady was listed a limited participant in Thursday's practice, along with running back Fred Taylor and fellow starters safety Patrick Chung (knee), guard Stephen Neal (shoulder) and defensive lineman Mike Wright (groin).
It's unclear when Brady sustained the injury, and if it occurred in Sunday's loss at Cleveland. The quarterback, who was 19-of-36 passing for 224 yards against the Browns, conducted his regular Wednesday news conference.
The oft-injured Taylor hopes to play Sunday night after missing five games with two painful toes.
He returned to practice on Wednesday and was there again Thursday, both with limited participation. The toe injuries on each foot have improved and the Patriots will announce his status for Sunday's game on Friday.
Taylor missed 10 games with an ankle injury last season, his first with the Patriots. This season he gained 98 yards on 25 carries before being sidelined when he suffered tendon and ligament damage in his second toe injury. At one point, he was afraid it might require surgery.
"The initial prognosis was bad, to the point of tears," he said. "I'm just happy to be at the point that I am because the past six, seven weeks have been pretty frustrating."
The Associated Press contributed to this report.