The NFL Live crew reacts to Calvin Johnson's recent comments on the Lions' fortunes playing a part in his decision to retire. (1:56)

A year after retiring, Calvin Johnson has admitted that playing for the Detroit Lions was a factor in his decision to walk away from the NFL.

When he retired last year, Johnson cited the beating his body was taking after nine years in the NFL as the reason he left the league. Last week in Italy, Johnson was more candid about the Lions' fortunes being just as important in his decision.

Johnson, who was in Italy to present the game ball for Italian Bowl XXXVII, the American football championship game in the country, was asked by reporters if he ever thought about switching teams.

"Of course, I thought about it," he said. "Just like in basketball, you know, guys, they create these superteams. But it's not quite like that in football where I had the freedom just to go.

"I was stuck in my contract with Detroit, and they told me, they would not release my contract, so I would have to come back to them. I didn't see the chance for them to win a Super Bowl at the time, and for the work I was putting in, it wasn't worth my time to keep on beating my head against the wall and not going anywhere.

"It's the definition of insanity," he added, drawing laughter from the media in attendance.

Asked again if playing for the Lions was the reason he retired, Johnson said: "Yes, and the body."

Johnson, 31, was interviewed for ESPN's E:60 last year three months after retiring and largely deflected questions whether the Lions' failure on the field led to his retirement. The furthest he would go was saying, "if [the Lions] would have been a contender it would have been harder to let go."

Johnson, a six-time Pro Bowl selection, made the postseason only twice with the Lions (in 2011 and '14).

Johnson's comments last week came two months after he told the Detroit Free Press that he wasn't happy with how the Lions treated him on his way out. The team also made him repay $1 million of his signing bonus when he retired.