"People will have their guesses and their opinions on my character, but anyone that's actually sat down and talked to me knows that I don't have any character issues, any off-the-field issues," Mayfield said Thursday night during a conference call after being selected the 2017 Manning Award winner.
Mayfield, who passed for 4,627 yards and 43 touchdowns, is the first Sooner and first former walk-on to win the Manning Award, which is given to the nation's top college quarterback. It is the only award to consider postseason performances in voting by a national media panel as well as Archie, Peyton and Eli Manning.
Mayfield also won the Heisman Trophy this season. After racking up prestigious accolades for his performances during live snaps, Mayfield said he is eager to meet with NFL coaches and front-office personnel and explain why some of his antics after the whistle and his behavior off the field won't be an issue going forward.
Last offseason, he was arrested on public intoxication charges, for which he reached a plea deal. His sportsmanship also was scrutinized after he planted a flag on the field after a victory at Ohio State and after he made an obscene gesture toward opponents during a lopsided victory at Kansas.
"Mistakes happen. I feel like I've owned up to those mistakes and I've grown and learned from them," Mayfield said. "So just moving forward, getting in front of [NFL coaches and front-office personnel], I think that's going to be the first thing I address. And then after that, it's going to be about playing ball, competitiveness, about how much I care to win and how much I will do to achieve that."
One person who does not need to be convinced is Archie Manning, who said he knows Mayfield personally as a participant in the Manning Passing Academy.
"We're all crazy about Baker and thoroughly enjoyed his career," Manning said. "He plays the game with passion. ... That's why he's been successful. I think that's why he'll continue to be successful."
Mayfield led the Sooners to a Big 12 championship and a semifinal berth in the College Football Playoff. But he said the semifinal loss to Georgia in the Rose Bowl Game presented by Northwestern Mutual still hurts and haunts him.
"Still haven't really gotten over it," he said. "Still having nightmares about some of the reads and some of the throws I made."
Now, Mayfield asserts he will prepare for the NFL draft the same way he prepared to prove himself as a college -- his numerous football honors notwithstanding.
"This type of training, it's the type of stuff that I thrive on," Mayfield said. "I know how to work. Not everything was given to me. I had to play the cards I was dealt, get better mentally, physically, push myself to limits that I didn't think I was capable of, so this is another one of those scenarios."
Mayfield, now working out in California, said he was in the gym recently when he noticed on TV that several draft projections did not list him among the top four quarterback prospects.
"So it's the same thing over again, which is why I'm going to enjoy this," Mayfield said. "Winning speaks for itself -- competitive nature -- those go a lot farther than any height and weight, any big arms can take you."
Other finalists for this year's Manning Award were Ohio State's J.T. Barrett, Clemson's Kelly Bryant, USC's Sam Darnold, Alabama's Jalen Hurts, Louisville's Lamar Jackson, Penn State's Trace McSorley, UCF's McKenzie Milton, Oklahoma State's Mason Rudolph, Auburn's Jarrett Stidham and Arizona's Khalil Tate.