Gronkowski, who was listed as questionable by the club earlier Friday, injured the hamstring Aug. 15 in a joint practice with the Chicago Bears and has been limited since.
On Thursday, when asked whether he was 100 percent, Gronkowski said, "No, I'm not. Since that one time during practice versus the Bears, I've just been week-to-week with a little hammy thing. So it's just been week-to-week, day-by-day, but I'm feeling good."
Gronkowski said his availability for the game "boils down to a coaching decision, the medical team, and myself; we'll all get together and collaborate and see where I'm at."
Gronkowski's absence takes away a top weapon from third-year quarterback Jimmy Garoppolo,who is making his first career regular-season start. The Patriots have three other tight ends on the roster, with Martellus Bennett likely to fill the biggest part of the void. Clay Harbor andAJ Derbyalso are on the depthchart.
In addition to Gronkowski, starting left tackle Nate Solder and right guard Jonathan Cooperwere downgraded to out.