Rob Gronkowski retires (again) from NFL: Why we hope this one doesn't stick either
Rob Gronkowski's Agent Reveals 'Gut Feeling' on Comeback
Rob Gronkowski refuses to rule out NFL comeback, NFL News
22 NFL players who retired early, from Gronk to Barry Sanders
Rob Gronkowski: Former NFL player isn't making a comeback, he's hawking CBD oil
Rob Gronkowski Announces 2nd Retirement From NFL
End of the NFL for Gronk after retirement announcement
Former NFL player believes we've seen the last of Rob Gronkowski after his recent retiring
All-Pro tight end Rob Gronkowski retires again - The Japan Times