Retired Detroit Lions wide receiver Calvin Johnson is beginning to open up about all the reasons he decided to retire at age 30.

It's long been understood that Johnson was stepping away because of nagging injuries, but the future Hall of Famer has now confirmed the plight of the Lions' organization was a factor in his decision.

"If we would've been a contender, it would have been harder to let go," Johnson admitted in an interview with Michael Smith of ESPN.

In nine seasons as a pro, Johnson went to the playoffs only twice, and the organization never put a team in place around him that had a legitimate chance to contend for a Super Bowl.

Johnson also divulged information about his injury history, that included multiple concussions.

"It's clear to see when you get a concussion. In football, it's - concussions happen, if not on every play, then they happen like every other, every third play, you know. With all the helmet contact, guys hittin' the ground, heads hittin' ground. It's simply when your brain touches your skull from the movement or the inertia, man. It's simple to get a concussion, you know. ...I don't know how many I've had over my career, you know, but I've definitely had my fair share."

The entirety of Johnson's interview will air on Thursday, July 7 on ESPN.