"Left Cleveland, goes down to Cincinnati," Mayfield told reporters in November 2018. "I don't know. That's just somebody that's in our locker room asking for us to play for him and then goes to a different team we play twice a year. Everybody can have their spin on it, but that's how I feel."
"I still think this guy is going to be a really good player. … The player, I've never had a problem with the player," he said.
Jackson was head coach of the Browns for the first eight games of Mayfield's career in 2018. He was originally hired by the team in January 2016, but he was fired midway through his third season after posting a 3-36-1 record.
After Jackson was fired by Cleveland, he accepted a position with the Cincinnati Bengals as an assistant to head coach Marvin Lewis.
Jackson's decision to go to a division rival rubbed Mayfield the wrong way.
The two had an awkward handshake exchange on the field after Cleveland's 35-20 win over the Bengals in Week 12.
Mayfield is looking to bounce back in 2020 under new head coach Kevin Stefanski. The 25-year-old completed just 59.4 percent of his passes for 3,827 yards with 22 touchdowns and 21 interceptions, as the Browns stumbled to a 6-10 record last season.
Jackson hasn't been hired by an NFL team since finishing out the 2018 season with the Bengals.