Jamal Adams better sleep with one eye open ... 'cause Rob Gronkowski is vowing REVENGE on the Jets safety for his brutal attack on the Patriots' mascot!!!
ICYMI ... J.A. was playing around at Pro Bowl practices last week -- when he went after Pat Patriot and tackled the poor guy to the ground.
Turns out ... Adams really hurt the dude -- NFL Network's Ian Rapoport says the person in the costume is still "dealing with jaw, neck, and back soreness."
Enter Gronk ... who told reporters at Monday night's Super Bowl media day that he's not just gonna sit around and let a New York Jet do that to his team's biggest supporter.
"We're going to have to figure a way out to get the revenge. That was not nice what he did. I heard the guy got seriously hurt!"
The 2019 schedule hasn't been released yet ... but we know the Pats will play Adams' Jets TWICE next season.
If Gronk doesn't end up retiring after Sunday's game ... better keep your head on a swivel, Jamal!!!