Patriots tight end Rob Gronkowski announces his retirement on Instagram

FOXBOROUGH, Mass. (AP) — Patriots tight end Rob Gronkowski announces his retirement on Instagram.View this post on InstagramIt all started at 20 years old on stage at the NFL draft when my dream came true, and now here I am about to turn 30 in a few months with a decision I feel is the biggest of my life so far. I will be retiring from the game of football today. I am so grateful for the opportunity that Mr. Kraft and Coach Belichick gave to me when drafting my silliness in 2010. My life e