Ex-NFL Star Jamal Lewis Warns Tua, Head Injuries 'Can Haunt You For Rest Of Your Life'

Ex-NFL star Jamal Lewis says Tua Tagovailoa needs to be very, very careful with his health going forward after suffering a concussion last week ... telling TMZ Sports effects from similar head injuries that he's experienced in the past have lingered "for years."

"This is a silent creeper," Lewis said of post-concussion symptoms, "that can haunt you for the rest of your life slowly."

Lewis, unfortunately, knows all about head trauma -- the former Baltimore Ravens running back sustained several concussions in his career ... including one in 2009 that he says was a horrifying experience.

The ex-tailback says he was knocked out during a game, and didn't feel quite right following the hit for months. At one point while trying to recover, he says he "woke up not really recognizing myself."

The 43-year-old -- one of only eight people to ever rush for more than 2,000 yards in an NFL season -- is now telling Tagovailoa to use him as a cautionary tale ... and truly take care of his head before returning to the field.

"You gotta be more smart and understand that you might have a family," Lewis said, "that you have other people that are more important than this game."

Tagovailoa appeared to suffer a head injury initially against the Buffalo Bills on Sept. 25.

After telling docs it was his back, not his head, that bothered him, he was allowed to return to the game and then play again four days later against the Cincinnati Bengals.

In that game, he was slung to the ground and knocked out for several moments. He was rushed to the hospital, and has since been away from the Dolphins recovering.