Four-time Super Bowl champion Rob Gronkowski retires from NFL for second time, NFL
Rob Gronkowski Announces Retirement
Rob Gronkowski Announces Retirement From NFL, Again - E! Online
Patriots tight end Rob Gronkowski announces he's retiring
Rob Gronkowski retires again, but could make another comeback in 2022 or 2023, agent says (report)
Rob Gronkowski Retires: Patriots Tight End Is Best In NFL
Detroit Lions nearly traded for Rob Gronkowski, but the Patriots TE threatened retirement - Pride Of Detroit
Rob Gronkowski retires, won't join Tom Brady for 3rd season in Tampa Bay
Rob Gronkowski announces second retirement from football
Rob Gronkowski threatened to retire after he almost got traded to the Lions
Bucs Trade for Future Hall of Famer Rob Gronkowski