Rob Gronkowski's retirement will end THIS SEASON ... so says ex-Patriots TE Jermaine Wiggins, who tells TMZ Sports, "You heard it here first, he's going to be back this year!"
30-year-old Gronk famously hung up his spikes this past spring ... but there haven't been many people who have believed he's truly done with football.
Wiggins -- who's still plugged in with the Patriots -- says count him on the side that thinks Gronk's going to make a comeback ... telling us, "I would bet money -- at this point in time, I'm, like, 97% sure he's going to come back."
And, why? Jermaine thinks Rob is just going to miss playing too much to not eventually come walking back into Bill Belichick's locker room later this year.
"He loves the limelight," Wiggins says ... "And, what better way to keep continue to build the Gronk brand by being out on the field?"
As for how successful Gronk will be after such a long layoff from football, Wiggins says he thinks the future Hall of Famer will have no trouble getting back into form.
In fact, Wiggins tells us he thinks the time off will actually HELP Gronk!!
"He's still got plenty of gas left in the tank," Jermaine says ... "He'll be back. I'm telling you. Watch."