The starting center for the University of Alabama discovered an ugly side to his quarterback in their time together as roommates during fall camp.
"He's messy," Jones said. "He kind of leaves things everywhere. I was like, 'AJ, I'm not your maid. I'm not going to clean up your trash.'"
Jones also realized that McCarron likes to talk -- a lot -- but not polite conversation like "How's the weather?" or "How's the family?"
"I love messing with him," McCarron said. "We had a little thing last night. Everything he said I just disagreed with, even if he was 100 percent correct. And he finally looks at me, rolls his eyes and says, 'I'm going to bed.' I was like, 'All right, just go.'"
The bond between center and quarterback has taken on the feel of Felix and Oscar in "The Odd Couple," the brainy center trying to teach the unruly quarterback the ways of the world.
But it wasn't always this way. Not that long ago, few people, if any, knew what the strong-armed quarterback from south Alabama was like. He was too busy trying to become the starter at first. Then he had to earn the respect of his teammates.
"They told me what they thought, and I agreed with it or said, 'OK,' and 'We'll try,'" McCarron said. "Now it's kind of like if I see it, we're going to go with it, and that's how we're going to do it."
That confidence to lead began to take root during the national championship game in January, when coach Nick Saban gave him the reins and told him to go win it.
In his first 13 games, McCarron averaged fewer than 11 pass attempts on first down, only four per game going for more than 10 yards. Against LSU in New Orleans, McCarron threw the ball 20 times on first down, completing six passes that moved the chains.
"Coach gave me the opportunity to come out and put the ball in my hands and let me make some plays," McCarron said after beating LSU. The two laughed about a scuffle during the regular season against Florida and talked about all the hard work that went into winning Alabama its 14th title.
The faith shared between coach and quarterback has brought out a new, fiery side in McCarron. With Saban's backing and a number of leaders gone from a year ago, McCarron's personality isn't stuck in the background any longer; it's being imposed on his teammates.
"AJ's one of those guys that knows what everybody's supposed to do on every play," Saban said. "We ran a draw in the scrimmage, and Cyrus [Kouandjio] missed a block. AJ said, 'If you make that block, we would have been out the gate.'
"He knows who is supposed to block everybody on every pass pickup and protection. He knows how the guys are supposed to run the routes and what the depth is supposed to be and when they don't do it the right way."
McCarron has always been an intense competitor. Said Saban, "Every play that doesn't work in practice, you can see him kicking the sand."
Like Saban, McCarron put away the national championship almost as soon as it ended. That wasn't his team, and he wasn't the same quarterback as when he left the Superdome.
"We can't live in the past," he said. "It's a different team, different leaders."
The new-look Crimson Tide will have their first test against the No. 8 Michigan Wolverines on Saturday. A number of rookies will be on the field for Alabama. For McCarron, it will be a chance to build on what he started at the end of last season.
McCarron said he stayed away from most of the post-championship publicity, something that former Alabama quarterback Jay Barker said kept many of his teammates away from football during the summer after the Tide's 1992 national championship. They started the following year in the top 10 -- only to lose three games down the stretch and cost the team a chance to return to the title game.
"I don't think you mean to be complacent, but you just go, 'Wow. Maybe I need to take a breath and step away from it a little bit,'" Barker told ESPN.com in March.
Instead of giving in to the distractions, McCarron spent much of the offseason preparing for his opponents with the help of graduate assistant Jeff Norrid.
"We broke each opponent down week by week but probably in the past two, two-and-a-half weeks, we've watched tons of film on [Michigan]," McCarron said. "Me and him are up here at least 3½, 4 hours a day. We'll come an hour or so before practice and then the rest after."
Michigan coach Brady Hoke has been watching film, too. As Hoke went through last year's tape, he started to see what has Alabama fans excited about the future with No. 10 under center.
"The more I watch him, the more you love him as a quarterback," Hoke said. "I think he's decisive. I think he does a nice job of going to the right guy. He's got good touch on the ball.
"He's a heck of a quarterback, and you'd expect that from a national championship team."
Jones has seen McCarron grow since beating LSU and said he expects "great things" in his encore performance.
During fall camp, he couldn't wait for McCarron to shut up. Now, quarterback and center are on the same page, and the future for Alabama is looking good.
"He's responded well so far," Jones said. "A lot of times we talk about what we're seeing, whether I'm helping him learn something about the defense. He's really starting to understand why I'm making my calls.
"It's kind of the next step for a quarterback."