He was less certain in 2010, after he had thrown all of six passes for the Carolina Panthers the previous two seasons. He struggled to get another N.F.L. job because teams had such little film of him, and he spent the next season with the Hartford Colonials of the United Football League.
Weary of waiting for a phone call, McCown reconnected with Chadwick, whom he had met in early 2010. McCown lived in Waxhaw, about two miles from the school.
Their philosophies aligned, and from the outset McCown was honest: If an N.F.L. team called, he was going. The Mavericks hoped he would never leave. They also hoped he would.
Approaching the unpaid position like a full-time gig, McCown immersed himself in the program. He hosted film review sessions, replete with homemade lasagna, at his house. After practices, he would text players to share ideas — or sometimes just to check in with them, to ask about their math test. He scouted opponents, attended junior varsity games, served as the scout-team quarterback.
“The last thing he needed to be doing was hang out on a high school field with a bunch of kids he’s never met before,” Mavericks running back Jacob Henderson, who now plays at Gardner-Webb University in Boiling Springs, N.C., said in an interview last month in Charlotte. “We all wondered: Is he going to be here? Is he not? Josh went above and beyond. He put his heart and soul into it.”
McCown said he never considered otherwise.
“I thought the impact would be lessened if they felt like you were half-in, half-out,” McCown said of his involvement with the Mavericks. “I didn’t want them to respect me because I played. I wanted them to respect me because I cared about them.”