Johnny Manziel discusses the issues he had with alcohol and the road it led him down. (0:41)

Johnny Manziel and Baker Mayfield are both from Texas and "have a really cool friendship," but the comparisons should stop there, Manziel said on Barstool Sports' Pardon My Take podcast.

"We're completely different people. We have a similar background. We're both from Texas. We both played Texas high school football, but he's not me, and I'm not him. The way my wires are in my head and the way that I'm built and my makeup is completely different than Baker," Manziel said, according to Ohio.com, which transcribed the quarterback's comments.

At the Reese's Senior Bowl last month, Mayfield acknowledged that people try to portray him "as a bad boy, the Johnny Manziel stuff" but told reporters, "I love the game of football, there's no doubt about that. I'm an emotional player. I'll do anything it takes to win. I love being around my teammates, leading and having responsibilities. It is what it is. If I paid too much attention to it, I'd be focusing on the wrong things."

Mayfield, who is expected to be one of the first four quarterbacks selected in April's NFL draft, has had off-field trouble -- he reached a plea deal after an arrest on public intoxication charges in February 2017 -- and has been criticized for on-field antics, such as planting a Sooners flag on the field at Ohio State after a victory and making an obscene gesture toward Kansas players during an Oklahoma rout.

"Baker is fiery as hell. He gets a little amped up on the sidelines. Once you're on the football field and you do some things that are a little outlandish, like guys do that all the time. Was it maybe a little bit too much? Sure. But at the end of the day, the guy made a mistake, he paid his dues and I think he'll be better off because of it and he'll learn from that," Manziel said on the podcast.

Manziel says he has "all the faith in the world in" Mayfield.

"I think he's going to be a really good player, and if anything, people can compare him to me, but he can learn from what I did wrong. He can try and take something that I did and make it a positive for him."

The Barstool Sports podcast was released Monday, as was Manziel's interview with ABC's "Good Morning America" in which the former Heisman Trophy winner said he has been diagnosed as bipolar and is taking medication for it and that his goal is to get back on the football field.