ABC News' John Muller and Kimberly Berryman report:

The Utah volunteer youth football coach who was arrested after allegedly stepping onto the field and striking a 13-year-old player down says he was acting in self-defense.

"It was a defensive position," Nathan Harris, the assistant coach for the Mapleton City's football team, told ABC News. "I never crossed the line. No harm [was] meant to be done."

Harris was coaching his sons' youth football team last month in one of the last games of the season. As the opposing team's fullback was headed for a touchdown in the Oct. 6 game, Harris allegedly stepped onto the field in Payson City, Utah, and struck the 13-year-old player down.

"What I saw was the Payson player running toward the Mapleton sideline," said the game referee, David Durrant, at the time. "What I saw was the Mapleton coach didn't even try to move. He just raised his arms and hit him with his forearms, is what it looked like."

Durrant threw a yellow flag and Harris, a father of six, was thrown out of the game.

After video of the confrontation went viral, Harris was arrested by the Payson Police and charged with second-degree felony child abuse charge over the allegation that he hit the seventh grade football player, a charge punishable by up to 15 years in prison. He was freed after posting $5,000 bail, according to authorities.

The boy, whose name has not been released, reportedly suffered a season-ending concussion. Because the boy did not suffer "serious" physical injury under the legal definition, however, the felony charge against Harris was dropped by Utah authorities last month.

Harris has been charged with a misdemeanor assault and will appear in court next month.

Harris' attorney, Rhome Zabriskie, says that a new video, shot from a different angle than the one widely seen, backs up his client's claim that his action on the field was in self-defense.

"The video speaks for itself," Zabriskie said. "You defend yourself. If you see a helmet coming at you at 20 miles an hour, you're not going to let it hit you in the chin."

The victim's mother told a local TV station after the game that Harris "flattened" her son and that the scene was the "most awful thing I've witnessed in my life."

Harris says he should not be charged with a crime but understands how the opposing player's mother feels.

"I took the hit," he told ABC News. "It might have been a different story if my son had been hit in the head."

ABC News' Annie Rose Ramos contributed to this report.