A soccer referee in the US died after he was punched by a teenage player.

46-year-old Ricardo Portillo from Salt Lake City, who had been in a coma, passed away in hospital this morning.

The 17-year-old suspect assaulted him after the referee had shown him a yellow card for a foul in a match last weekend.

Portillo was struck in the face and suffered swelling to his brain.

The teenage player has been sent to a juvenile detention facility on suspicion of aggravated assault.