The former No. 1 overall pick in 2018 told ESPN's Jake Trotter that facing his first real adversity on the field last season weighed on him both mentally and physically:
"Having success all through high school and college and having that standard so high, and the past couple of years have just been a roller coaster of emotions and not nearly as much success as I'm used to. So I would say I lost myself, not having that success, not finding out what was working. I think I tried different ways of trying to have that success, and I didn't find it.
"So I lost myself in that, and I wasn't able to be who I [need to be] for these guys on the team."
Mayfield lost just nine games in four years of college football at Texas Tech and Oklahoma. He's already gone 12-17 as an NFL starter, losing more games in 2019 (10) than he did during his entire NCAA career.
It was a lot to take in. And with the grueling nature of a professional season, he couldn't adjust the way he wanted to.
"I think there was a lot of plays—looking back on last year—physically, I wasn't able to work out as much, being beat up," Mayfield said. "So I was heavier than I was ever playing before... I needed to be able to have the scrambling ability to move in the pocket. It's my job to be in prime physical shape, to show up and do my job on Sundays."
The third-year pro dealt with multiple wrist injuries last season and saw both his completion percentage (59.4 percent) and yards per attempt (7.2 yards) drop a bit from his rookie campaign. To ensure that doesn't become a trend, Mayfield told Trotter he hired a dietitian, cut weight and worked on his speed in the pocket.
As a mobile quarterback, the last thing he wanted was for a broken play to become unmanageable because of his maneuverability.
"I'm in a much better state," Mayfield said. "I put in the work. ... [I'm] just ready to roll, attack, get back to where I need to be to be the leader for this team, for this franchise. The reason I've gotten here is because I've been myself, been able to attack each and every day with 100 percent effort."
If things work out as planned, Mayfield could deliver Cleveland its first winning season since it went 10-6 in 2007.