Rob Gronkowski Retirement: Tom Brady, Bill Belichick

BOSTON ( -- New England Patriots tight end Rob Gronkowski announced his retirement in an Instagram post on Sunday evening, and it was followed by a flood of reaction from teammates, other athletes and celebrities.

Tom Brady paid tribute to Gronkowski in an Instagram post:

Robert Kraft and Bill Belichick released statements through the team sharing what the tight end meant to them and the franchise.

Gronkowski's model girlfriend, Camille Kostek, commented on Gronkowski's post, saying, "Words can't express how proud I am of you. It has been an absolute thrill watching you perform like no other out on that field. You are the best that has ever played the game if you ask me! I love you with all my heart! I will be your biggest fan in all that you do!"

Many others reacted to the news on social media:

Boston Celtics stars Kyrie Irving and Gordon Hayward also expressed their appreciation for Gronkowski following a blowout loss to the San Antonio Spurs on Sunday night.