It (sort of) looks that way, according to Zachary, our tipster. But it's tough to be sure. That pose you see above is certainly Gronk-like, but dude's also wearing a shirt with buttons, and we can't tell whether he's also wearing Zubaz. Another photo shows dude drinking from a bottle of water, which only adds to the intrigue.
Zachary says these photos were taken Sunday at a bar in Manhattan's Flatiron District. That would be the day before Gronk was scheduled to have more surgery on his forearm at a hospital in Boston.
I arrived at 5 and left at 8:30. The photos were taken at 6pm and probably 7pm. He was there when we arrived and still there when we left.
Then again, Gronk's surgery wasn't until Monday afternoon. It's the Summer of Gronk. All things seem possible, especially Sunday Funday.