If Bo Jackson knew what he knows now about concussions and how they’ve had a massively negative impact on many retired NFL players today, he probably would have never played football.

He just would have been known as a really, really good baseball player.

“I don’t think anyone who has ever strapped on the helmet and shoulder pads hasn’t had their bell rung,” Jackson said in an interview with MMQB. “I had my bell rung once. It’s not anything to play with, now I know that. I went and watched the movie (Concussion) and there were people I knew, that I was friends with, that were gone that I didn’t even know they were gone.”

Jackson rushed for an Auburn record 4,303 yards and 43 touchdowns during his four-year college career (1982-85) with the Tigers and won the Heisman Trophy as a senior before producing 2,782 yards on the ground and 16 scores for the Los Angeles Raiders (1987-90). He also spent nine seasons playing for three different teams in the MLB, finishing as the only person to ever be selected for a Pro Bowl and an MLB All-Star game.

“If I had young kids, to be honest, and if they came and said, ‘Dad, I want to play football,’ I’d smack them in the mouth. ‘No. No,'” Jackson said. “Because if I’d have known back then what I know now, to be honest with you, I probably would have taken a different path. I probably just would have played baseball.”