Calvin Johnson retired from the NFL last offseason at the ripe old age of 30. In nine seasons with the Lions, the team that drafted him second overall in 2007, Johnson racked up 731 receptions for 11,619 yards and 83 touchdowns. And while Johnson was never listed as suffering a concussion during his career, that doesn't mean it didn't happen.

"Guys get concussions, they don't tell the coaches," Johnson said Saturday, according to the Detroit Free-Press. "It happens. I don't tell the coach sometimes cause I know I got a job to do. The team needs me out there on the field. And sometimes you allow that to jeopardize yourself, but that's just the nature of the world."

So had Johnson ever concealed a concussion from Lions team doctors?

"Of course," he said. "They're going to dispute that, but anytime you black out, anytime you hit the ground and everything is stars and stuff, any time your brain hits your skull, that's a concussion. No matter how severe it is, it's a concussion. Now granted, some people get nausea. That's a severe concussion when you get hit like that and you get nausea and stuff like that. But if you play football long enough [you're going to have concussions]."

Johnson's comments come days after Tom Brady's wife, Gisele Bundchen, told "CBS This Morning" that the Patriots quarterback suffered a concussion sometime last year, though it was never listed on an injury report. Hours after Bundchen's interview, the NFL released a statement saying that there was no evidence that Brady had suffered a concussion during the 2016 season.

And days after that, Brady's agent said the concussion didn't happen.

Meanwhile, Johnson's comments come 10 months after he said he suffered his "fair share" of concussions during his playing days, though he was never listed on a injury report.

"With all the helmet contact, guys hitting the ground, heads hitting ground," Johnson told ESPN in July 2016. "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."

In October 2012, three years before Johnson retired, he said he was concussed on a big hit from Vikings linebacker Chad Greenway. Then-Lions coach Jim Schwartz disputed Johnson's concussion claim.

"Our evaluation was he was not concussed," Schwartz said at the time. "He was thoroughly checked. We were very strong in our evaluation. He was cleared to go back in the game, and he was on a protocol after that, and he was cleared then."

Last week, Johnson was asked about the possibility of the Lions retiring his jersey.

"I don't even like to talk Lions too much just because the way our relationship ended," he said, via the Free-Press. "If they see me around here, we'll see. But hey, I don't know."