Tyrann Mathieu Says There's Still Hope for Johnny Manziel If He Does This

Johnny Manziel can still resurrect his NFL career, so says Tyrann Mathieu -- but he's gotta do one fundamental thing to complete his comeback.

We spoke with Honey Badger on the TMZ Sports TV show (airs weeknights on FS1) ... and since he's got one of football's best redemption stories, we asked him what Johnny should do to follow suit.

Tyrann's main piece of advice -- tune out the haters!!

"We get to certain points and certain stages in our career where we start to take other peoples’ opinions more than our own," Mathieu said.

"We stop believing in ourselves. We start believing in other people and what they’re saying."

And if Manziel gets that self-belief back -- "He’ll be alright."

FYI, we got Johnny out in L.A. over the weekend ... and it looks like he's already on his way!!