Throughout his nine NFL seasons, Calvin Johnson was always a quiet character. The soft-spoken Megatron has been just as mum on his reasons for retiring from the gridiron at 30.
After the Detroit Lions announced in March that the six-time Pro Bowl receiver would indeed hang up his cleats, Johnson gave a glimpse into his decision process in a sit-down with ESPN's Michael Smith for "E:60," which aired Thursday night.
Johnson gave several reasons for retiring, from current health, to future health worries, concussion concerns and mental fatigue.