Rob Gronkowski threatened to retire after he almost got traded to
Rob Gronkowski Announces 2nd Retirement From NFL
Four-time Super Bowl champion Rob Gronkowski announces retirement
Rob Gronkowski Announces Retirement From NFL, Again - E! Online
NFL News: Patriots tight end Rob Gronkowski announces his
GoLocalProv Gronkowski Announces Retirement on Instagram
Rob Gronkowski announces retirement from NFL – Boston Herald
Texans' J.J. Watt salutes Patriots TE Rob Gronkowski's retirement
Rob Gronkowski Announces Retirement From NFL