LA QUINTA, Calif. — Jeff Sperbeck, a close friend and business associate of John Elway, died Wednesday morning — a little more than three days after he fell off a golf car driven by the retired Denver Broncos quarterback.

The incident occurred Saturday at a gated golf community in Southern California where Elway owns a home.

That Elway was driving after he and Sperbeck had attended the Stagecoach music festival was first reported by TMZ. A source familiar with the details of the incident independently confirmed to 9NEWS that Elway was driving.

A source close to Elway told 9NEWS he is devastated by the tragedy involving his close friend.

The accident occurred at the Madison Club in La Quinta, a private golf resort community. According to TMZ, Sperbeck was seated on the back of the golf cart when he fell off and struck his head on the pavement.

It was Elway who called 9-1-1, according to the TMZ report. The local fire department and ambulance paramedics serviced the call. The local sheriff’s department did not respond to the call, although it is now.

“The Riverside Sheriff’s Office was informed of the incident on Monday, April 28th, and opened an investigation,” public information officer Lt. Deirdre Vickers stated in an e-mail to 9NEWS. “At this time, the investigation is ongoing, and no details are available.”

Sperbeck was found breathing but unconscious and transported to a hospital in Palm Springs, where he died.

Sperbeck had been an NFL agent to more than 100 players, coaches and executives. He was the type of agent and marketing rep who stayed in touched with his clients long after the NFL careers ended.

When one of Sperbeck’s clients, former Broncos and Peyton Manning quarterbacks coach Greg Knapp, was killed four years ago while riding his bicycle by a driver distracted by his cellphone, Sperbeck stepped up with great compassion.

He helped Knapp’s wife Charlotte not only with service arrangements, but in helping to found the Coach Knapp Memorial Fund that promotes distracted driver awareness and reform. The cause includes an annual stadium stair climb by NFL coaches as running the stadium stairs was part of Knapp’s pregame routines.

Before this accident, had you Googled Sperbeck’s name, a photo of Elway would have come up.

It was primarily because of their varied businesses partnerships, from 7 Cellars wine to the Elway restaurants, that this is so. Sperbeck has been Elway’s marketing representative since the latter’s prime as the Broncos’ superstar quarterback in the early 1990s, a relationship that grew into a close friendship.

When Elway was the Broncos’ general manager from 2011-2020, and the team was playing a road game out West, Sperbeck, who lives in Southern California, would almost always accompany him, standing near his side.