If Rob Gronkowski retires from football ... could he have a 2nd career in the WWE ring?!
That's what Gronk's best buddy, WWE superstar Mojo Rawley, hinted at before the Super Bowl ... just 1 day before Rob shocked the NFL universe by saying he might not be back in 2018.
Rob Gronkowski said he was going to reflect on his future when asked if he’s considering retiring.
He wouldn’t commit to returning in 2018. pic.twitter.com/ApdZKKMqyM
"It's not a matter of if, it's a matter of WHEN," Mojo told TMZ Sports, before adding, "I can't speak for him."
Hard to think Gronk -- injury (and concussion) history aside -- would call it quits at age 28 ... especially to get body-slammed in the ring.
That said ... you can't deny he's got the look.