Since quarterback AJ McCarron returned to professional football in 2023, he’s on his third season.

The former Alabama All-American made his comeback last year with the St. Louis Battlehawks of the XFL. McCarron then achieved his objective of returning to the NFL as a backup with the Cincinnati Bengals last season. But he still returned to the Battlehawks this year for the inaugural season of the United Football League.

While the physical challenge of a professional quarterback might be obvious, the job also can be a mental test as well.

“From a mental side of it is making yourself be disciplined,” McCarron said on Tuesday. “And when I say mental, it’s just being disciplined enough to do the right (expletive) you have to do and continuing to do it even though it’s a boring, slow process of watching what you put into your body or ‘Man, we don’t get a bye week, I have to go back up and watch film’ or earlier today we didn’t have to come in until 11, but I had to get some stuff done at about 9:30, I went to treatment for about two and a half hours and then we’ve been in meetings all day breaking down film since then and after this I’m going back to treatment for another two hours, so that’s a grind in itself.”

Being able to withstand that grind for McCarron started when he tore the anterior cruciate ligament in his right knee during a preseason game with the Atlanta Falcons on Aug. 21, 2021. While the injury sent the former St. Paul’s Episcopal star to injured reserve for the season and sidetracked his NFL career, he credits the setback with allowing him to lay the groundwork for his year-round return.

“Really truly, what’s helped me the most in my career was tearing my ACL, as much as I hate to say it,” McCarron said. “It really just changed my thought process behind what I was putting in my body. Talking to my doctors, Lyle Cain and everybody I was doing rehab with, was really just focusing on: This food causes more inflammation in the body and this type of food helps get inflammation out or helps deal with it and stuff like that. And then just watching my weight in general.

“I have people in my family now that are like, ‘Man, sometimes you look skinny out there.’ I’m like, ‘Well, I feel great.’ My body feels great. I feel like I can move a whole lot better. And the fact that, really and truly, people don’t think about it, but I’ve been going two years straight with no break in this thing, so I think, not to pat myself on the back, but I think it’s a testament to my routine and taking care of my body to be able to go two years straight non-stop.

“And I feel great, and I feel like I’m moving much better than I probably ever have. I would say tearing my ACL, as much as it sucked, and going through that whole process of rehab and everything, that really changed the thought process behind how I take care of my body.”

McCarron and the Battlehawks return to action at 2 p.m. CDT Saturday, when they play the Houston Roughnecks at the Dome at America’s Center in St. Louis. FOX will televise the game.

Halfway through the UFL regular season, the Battlehawks have a 4-1 mark. St. Louis takes a four-game winning streak into the game, with Roughnecks at 1-4.

This season, McCarron has completed 111-of-162 passes for 1,051 yards with 10 touchdowns and one interception. He leads the UFL in touchdown passes and ranks second in passing yards.

“AJ’s a very savvy, veteran quarterback that can get us in and out of bad plays versus not the right looks we want versus that particular play call,” Battlehawks offensive coordinator Bruce Gradkowski said on Tuesday. “He’s been a big help in that sense. And just me and my foundation of playing quarterback for Jon Gruden back in ‘06, starting 11 games as a rookie. He gives quarterbacks tools in your toolbelt, and any quarterback I coach is going to have tools to help them be the best they can be. And AJ’s a veteran that understands that and knows how to utilize that.”

Mark Inabinett is a sports reporter for Alabama Media Group. Follow him on Twitter at @AMarkG1.