Calvin Johnson opens up about his retirement

Former Detroit Lions wide receiver Calvin Johnson knew exactly when it was time to hang up his cleats.

Mentally, Johnson could continue to push himself, but his body slowly began to wear out. His basic morning routines became more of a chore and even his steps became labored.

In ESPN’s latest E:60 profile, Johnson sat down with His & Hers co-host Michael Smith in a candid interview to detail the struggles that lingered toward the end of his career.

Johnson, who was drafted second overall by the Lions in 2007, played his entire career in Detroit until announcing his retirement in March. While there, the receiver racked up 731 receptions for 11,619 yards in nine seasons.

Now, the 30-year-old reflected on his career. After being asked by Smith if he doesn’t play the game anymore because he can’t or because he doesn’t want to, Johnson paused briefly before responding.

“I think it’s a combination of both,” he said. “I can’t put in what I want to put in, what I used to put in to get the results that I used to get. I can’t put in those same efforts and I’m not going to sell myself short; I’m not going to go out there and not be 100 percent.”

During the course of the interview, Johnson also gave an honest take on the NFL’s treatment of concussions. Last season alone, there were 271 diagnosed concussions, an increase of nearly 32 percent from the 2014 season.

In the earlier days of Johnson’s football career, reporting concussions was nearly taboo. Now, according to Johnson, a team could get in trouble if a concussion a player may have sustained while on the field goes undiagnosed.

“It’s simple to get a concussion,” Johnson said. “I don’t know how many I’ve had over my career, but I’ve definitely had my fair share.

Catch the rest of Johnson’s interview Thursday at 10 p.m. ET on ESPN.