"The reason why we added Baker was to make the group better as a whole," Fitterer said after the Panthers officially completed their trade with the Cleveland Browns for the former No. 1 overall draft pick. "Sam is very much a part of this competition. ... I think they're both gonna rise and play their best football they have."
Fitterer added that there have been no discussions about extending Mayfield's contract yet as both he and Darnold head into the final year of their current deals. And he said there have been no discussions about trading Darnold.
"We'll let it play out throughout the season and we'll make decisions later in the season whether it's November or December, once there's a track record behind (Mayfield) in this offense and this organization. ... I just want to take it short term for now," said Fitterer, who added that rookie third-round draft pick Matt Corral will have the opportunity to "learn at his own pace" and learn from "some pros in the room" that also includes backup P.J. Walker.
Mayfield, meanwhile, said that Darnold reached out to him the day after the deal was agreed to last week and offered to help him with things like finding a place to live and arranging an informal workout session with new teammates before training camp starts in two weeks.
"It's gonna be special, and I think we're gonna help each other out quite a bit," Mayfield said of Darnold -- who was drafted two picks after him atop the 2018 NFL draft.
Mayfield said nobody at this level has the mindset of being a backup -- but vowed to fill whatever role the team has in mind while becoming "the best quarterback I can be ... a great leader and a great teammate."
One thing Mayfield has already secured, however, is the No. 6 he has worn since college -- thanks to the generosity of punter Johnny Hekker, who signed with the Panthers earlier this year but agreed to switch numbers.
"I did my own negotiating with Johnny," joked Mayfield, who said the No. 6 has become special to him and "symbolizes my story" even though it was initially chosen for him as a walk-on at Texas Tech.
Hekker joked to the Panthers' website that "gas prices are crazy these days, so you've got to do what you can do to keep the tank full."
"But in all reality, it's kind of a fresh start for both of us here in Carolina. You want a quarterback who can feel good about what they're playing in. I'm excited to get a fresh start in a new number for the first time in my career," Hekker said. "It'll be a great deal for Baker to have a little bit of familiarity, and feel himself in number 6."
Mayfield also mentioned his college journey from Texas Tech to Oklahoma when he said he is no stranger to the kind of transition he's making now. He also said that he "unfortunately" had to adjust to playing for multiple head coaches and offensive coordinators on an annual basis during his first four years with the Browns.
"The timeline is different (in this case)," said Mayfield -- who said he had already started to do "a lot of cramming" before officially receiving his playbook Tuesday.
But he and Fitterer both mentioned that his familiarity with current Panthers and former Browns offensive line coach James Campen and the terminology and protection calls will help with the transition.
Fitterer was asked about a March report from ESPN's Chris Mortensen that a Browns source had told him the team wanted to replace Mayfield with "an adult at that position." Fitterer said that he and the Panthers did ample homework before making the trade and said "a lot of people really went to bat for Baker," with some coaches even calling the Panthers unsolicited to recommend him.
"We're very comfortable with Baker, we're excited to add him to the room, and we look forward to working with him," Fitterer said. "In the end, it all came back that this is a fiery, competitive guy. He wants to win, he wants to be great. And I think as an organization we embrace that attitude."
Mayfield chuckled when he said he learned a lot of lessons from his highs and lows in Cleveland. But he said he cares more about how his teammates perceive him than media reports and that his "competitive nature will never go away."
"If I do that, then I shouldn't be playing anymore," Mayfield said.
Mayfield and Fitterer both acknowledged that it took a long time to eventually negotiate the trade, which included Mayfield agreeing to convert $3.5 million of his guaranteed salary into incentives (with the Panthers paying $4.86 million and the Browns paying $10.5 million).
"It was not a very easy past couple of months," said Mayfield, who said "I don't think there was any manual" for figuring out how to divvy up the salary to make such a deal work.
"For me it was about the next steps forward and finding a new place, somewhere that wanted me, somewhere I would go and compete."
The Browns will receive a fourth- or fifth-round pick in 2024 in exchange for Mayfield. Fitterer confirmed that Mayfield needs to play 70% of the snaps for the draft pick to become a fourth-rounder.
Mayfield said there is no animosity toward Cleveland, but he did acknowledge that being "shocked" is the only way he could describe his reaction to the team's decision to replace him through a blockbuster trade for Deshaun Watson.
And Mayfield told the Panthers' website that he is well aware that Carolina opens its season with a home date against Cleveland.
"I'm not going to sit here and be a robot and tell you that's not one I've marked on the calendar already," Mayfield said.
Unfortunately, though, Mayfield suggested that the moving experience won't become a new part of his advertising campaign with Progressive Insurance, for which he previously pretended to live at Cleveland's Progressive Field.
"I think that's a missed opportunity," Mayfield joked.