Dry your tears, Patriots fans ... if Chicago Bears star Kyle Long is right, Rob Gronkowski isn't going anywhere anytime soon, 'cause Long tells TMZ Sports all the retirement talk is just that ... talk.
After the Super Bowl, Gronk said he was pondering his future in football -- some think he'll actually retire.
But not Long -- who strongly believes Gronk has a lot of football left in him and will return to the Patriots next year.
So, what about Gronk's future as a Hollywood actor? Long's a fan -- telling us straight-up, "I know I'd pay 10 bucks to watch him f*ck around behind the camera!"