Calvin Johnson loses his helmet on a hard hit by a pair of Bengals defenders during a 2013 game. (Rick Osentoski/Associated Press)

Sometime soon, the NFL may have to explain in court how its team’s medical staffs responsibly dispensed painkillers to players in the league. According to Calvin Johnson, powerful and addictive opioids were, until recently, handed out “like candy.”

Johnson, who retired from the Lions in March after a stellar career, offered his thoughts on the lengths to which NFL players went to stay on the field in an interview with ESPN’s “E:60.”

“I guess my first half of my career before they really, you know, before they started looking over the whole industry, or the whole NFL, the doctors, the team doctors and trainers, they were giving them out like candy, you know?” Johnson said in an on-camera interview that is scheduled to air first on Thursday.

“If you were hurting, then you could get them. It was nothing,” Johnson added. “I mean, if you needed Vicodin, call out, ‘My ankle hurt,’ you know. ‘I need, I need it. I can’t, I can’t play without it,’ or something like that. It was simple. That’s how easy it was to get them. So if you were dependent on them, they were readily available.”

More than 1,500 former NFL players, not including Johnson, have filed a class-action lawsuit against the NFL, one that a federal judge recently ruled could proceed to the discovery phase. The suit, which names each of the league’s 32 teams, alleges that doctors and trainers often distributed painkillers without examinations or prescriptions, and that players were deliberately misled about their dangerous side effects.

“I know where my body’s at, know how it feels,” Johnson, 30, told ESPN of his decision to retire, which surprised many, given that he was coming off of another effective season. He had 88 catches for 1,214 yards, 10th in the NFL, and nine touchdowns in 2015, plus his sixth Pro Bowl selection.

“I know how it felt to one, get it to go every day,” Johnson said. “And to be out there actually doing it every day, you know — the pain to do it. You can’t take Toradol and pain medicine every day, you know. You’ve got to give that stuff a rest, and that was one thing I wasn’t willing to do.”

In April, a federal appeals court upheld the NFL’s settlement of another class-action lawsuit brought by thousands of ex-players, this one relating to the concussions and brain damage they suffered while playing football. Johnson said the Lions’ medical and training staff featured “good people” who nevertheless felt an imperative to get players “back on the field” as quickly as possible.

“Concussions happen,” he said. “If not on every play, then they happen like every other, every third play, you know. … It’s simple to get a concussion, you know. I don’t know how many I’ve had over my career, but I’ve definitely had my fair share.”

“The team doctor, the team trainers, they work for the team. And I love them, you know,” Johnson added. “They’re some good people. They want to see you do good. But at the same time, they work for the team. They’re trying to do whatever they can to get you back on the field and make your team look good.”

Many Lions fans have been hoping Johnson would reconsider his decision to retire and return to the NFL, but he reiterated in June that he was “not coming back.” He told ESPN, though, that he would miss playing football.

“You’re playing the greatest game against some of the best athletes in the world,” he said. “It’s a bone-crushing game, and you’ve got to love that about it, because it takes everybody to do their job right in order for you just to, just to sniff victory, you know? So, like I say, I love it, I loved it. I left it all out on the field, I feel like.”

Johnson did admit that the Lions’ return to mediocrity — the team went 7-9 last year, its third losing campaign in its past four seasons — made his decision to retire easier. “If we would’ve been a contender, it would have been harder to let go,” he said.