Legendary former quarterback Brett Favre is warning parents not to let their children play tackle football before the age of 14, lest they greatly increase their kids’ risk of eventually developing the neurodegenerative disease chronic traumatic encephalopathy (CTE).

In a public service announcement released Tuesday by the Concussion Legacy Foundation, the Green Bay Packers great is featured in a video in which he plays the middle-aged version of a football player who is first shown talking to his parents as a youngster and then as an adolescent.

After the adolescent tells his parents, “By the time I’m your age …,” the video shows him changing to Favre, who says, “ … I could be fighting depression, struggling to keep my thoughts straight.”

“I could become violent — even towards my own children,” Favre continues in the video. “When I’m your age, what will matter to me is not my youth football career, but that, like you, I’m a great parent and I can provide for my family.”

The Concussion Legacy Foundation cited a 2019 study by a team of researchers from Boston University that concluded for every 2.6 years of playing tackle football, an athlete’s risk of CTE doubles. Someone who played tackle football for 14.5 years, the study found, was 10 times more likely to develop CTE than someone who spent fewer years playing.

The Centers for Disease Control and Prevention published a study earlier this year in which the federal agency found that children playing tackle football between the ages of 6 and 14 sustained 15 times the head impacts of those playing flag football in the same age range — and 23 times more high-magnitude head impacts.

“Having kids play tackle football before high school is just not worth the risk,” the 51-year-old Favre said in a statement shared by the Concussion Legacy Foundation. “CTE is a terrible disease, and we need to do everything we can to prevent it for the next generation of football players.”

Favre, who played in the NFL for 20 seasons and set a record with 297 consecutive starts — 321 including playoff games — has spoken out in the past about the numerous concussions he suffered. He said in 2018 that while he considered himself “lucky” not to be in worse condition, he felt his short-term memory and ability to recall basic vocabulary had “gotten a lot worse.”

That year also saw Favre reveal he was uncomfortable with the practice of youth tackle football.

I just cringe,” he said then, “seeing a fragile little boy get tackled and the people ‘ooh’ and ‘ahh’ and they just don’t know. Or they don’t care. It’s just so scary.”

“It’s time to accept that CTE is not just a risk for professional and college football players, but also for high school players,” Concussion Legacy Foundation co-founder and former college football player Chris Nowinski said in a statement Tuesday, “and the best way to prevent CTE among football players is to delay the introduction of tackle football to reduce the number of years played.”

The Concussion Legacy Foundation claims a brain bank study of 65 high school football players who did not go on to play the sport in college or professionally found that 16 of them had CTE, and that of that group, 15 began playing tackle football before the age of 14. The organization noted that the prevalence of CTE among all former high school football players is unknown.

While Favre took this emphatic stance, he expressed ambivalence Tuesday about whether NFL players should be vaccinated against the coronavirus. In a CNN appearance with Nowinski to promote the PSA, Favre was asked about lingering vaccine hesitancy in the league, which has high rates of vaccination but some high-profile holdouts, such as Minnesota Vikings quarterback Kirk Cousins and Baltimore Ravens quarterback Lamar Jackson.

“There’s a great deal of uncertainty,” Favre said on CNN. “You hear one thing one day, and you hear something that’s totally different the next. And this is from experts, experts on both sides of the argument. You know, the vaccines that have been administered within the last six to eight months didn’t go through a 20- or 30-year human trial study that the FDA requires.

“So we’re sort of the human trials, if you will,” he continued, “and I think some people are frightened by that and the conflicting info that we’re all getting.”

Asked if he had been vaccinated, Favre declined to share his status, adding: “It’s not my place to say, ‘Get the vaccine,’ or, ‘Don’t get the vaccine.’ I think that’s a matter of choice.”