Per Michael Witmer in the Boston Globe:
The news was not all good on the Patriots front Sunday. Tight end Rob Gronkowski suffered a broken left forearm in the 59-24 victory over the Colts, according to an NFL source.
Gronkowski didn’t speak to reporters after the game, and wasn’t seen in the locker room.
The Jets played the Patriots tough in their last meeting this year in Foxborough, but a lot has happened since then. Specifically, the team's offense bogged way down, and their special teams has become a real problem. In other ways though, it is as if nothing has happened. Other than Trufant (who covered Welker very well in the last game) there haven't been any more cataclysmic injuries and while they went through two terrible games, their momentum is back on the upswing.
The Patriots looked extremely impressive in all three phases yesterday over the Colts, but the Jets tend to hang in games against the Patriots and losing someone as important to the Pats offense as Gronkowski will most assuredly make it that much easier for the Jets to stay competitive in the game against the Patriots. I always like when the Jets play a team with their best players available, but Gronk is in the early part of his career and is shattering record books so while I'd like to see the Jets beat the Patriots with Gronk on the field, I'm not going to complain if he can't go with a broken arm in three days against the Jets.
It's still going to come down to the Jets defensive line being able to apply pressure to Tom Brady as well as stop the run out of sub packages, but it's going to be an easier task without a talented player like Gronk causing havoc for the Jets in the pass and run.