Salt Lake County District Attorney Sim Gill also said he will seek to try the 17-year-old as an adult in the death of Ricardo Portillo, 46.
The charge is less serious than manslaughter. It carries a possible sentence of 5 years in prison for adults, but penalties can be less for juveniles.
Gill said it became clear in looking at the facts that the teenager's actions didn't amount to murder or manslaughter. "We did not believe we could demonstrate the premeditation or intent to justify those charges," he said.
The oldest of Portillo's three daughters, Johana Portillo, 26, declined to comment about the charges through family spokesman Tony Yapias.
Friends and family spent yesterday remembering Ricardo Portillo at a wake that was to be followed by an evening service.
The accused teen has been in juvenile detention since April 27 when the incident occurred at a recreational-league soccer match in a Salt Lake City suburb.
The teenager, whose name is being withheld by The Associated Press because he's a minor, turns 18 in October. His first court appearance has not yet been scheduled.
His attorney, Monica Diaz Greene, was not immediately available for comment.
The teenager was playing goalie when Portillo called a penalty on him for pushing an opposing player. The teenager began arguing with Portillo and then struck him in the head, authorities said. -- AP