Harris said he put up his arms to protect himself from the player. Video of the incident shows everybody around Harris also throwing up their arms to avoid injury, he said.
"It's what happens in football," Harris said. "All of a sudden there's a football helmet in your chest that is coming [at you] 20 mph. It's what happens at other sporting events. Players run into players. Players run into spectators."
However, Harris contends that no one, including players or coaches, intends to injure someone when a player careens into people on the sidelines.
"The player ran into me," he said. "At no point did I make any move forward in aggression. It was all reaction and defense."
Harris was acting as assistant coach during his son's Maple Mountaineers game against the Payson team. The two teams were tied when a Payson running back began moving the ball to the end zone for what would have been a tie-breaking touchdown. As the boy ran close against the field's boundary lines, authorities allege Harris stepped into the boy's path and raised his forearms, hitting the boy under the chin.
Court records allege the teen suffered a concussion.
But Harris said the teen popped right back up and continued to play the rest of the game. He said there was no medical break needed, and that trained medical personnel also witnessed the incident and have since told him they didn't notice anything in the teen's behavior that would have indicated he suffered a serious head injury.
Harris' attorney, Rhome Zabriskie, said Monday that the case boils down to whether the city can prove Harris intended to injure the boy. Zabriskie said the collision was an accident and not criminal in nature.
Zabriskie said the episode happened quickly, and Harris had a split second to react and put up his arms to avoid taking a helmet to the chin as the player veered into his path.
"He feels he did nothing wrong," Zabriskie said. "You can see over and over [in the video] that the coach did not step over the line into the field of play. There is less than a half a second for the coach to react before the kid's helmet comes into his chest. What a person does as a reflex, how can you call that a crime?"
Zabriskie said he's certain a jury will clear Harris of wrongdoing.
In the meantime, Harris said, the charges he's facing will make it more complicated for anyone considering volunteering at their child's sporting events, if authorities are prosecuting such incidents as criminal acts.
But he said he'll continue to support his son through volunteering.
"It's unfortunate that these are the things that are going to happen," Harris said. "Sometimes bad things happen to good people and you just have to deal with it."
KUTV Ch. 2's Oct. 10 report on the Little League Football assistant coach includes video of the Oct. 6 incident in Payson • http://bit.ly/R37rmB
ABC News posted this video of the collision on YouTube, shot from a different angle • http://www.youtube.com/watch?v=upgquIbIZbc