According to the Riverside County Sheriff-Coroner’s Office, Sperbeck sustained the fatal injury on Saturday evening, April 26, shortly after 7 p.m. The agency confirmed his death on April 30, noting that his next of kin had been notified.

According to the Riverside County Sheriff-Coroner’s Office, Sperbeck sustained the fatal injury on Saturday evening, April 26, shortly after 7 p.m. The agency confirmed his death on April 30, noting that his next of kin had been notified.

Sperbeck was reportedly riding with Elway at the time of the fall, PEOPLE previously reported. The longtime agent and friend was thrown from a moving golf cart under unclear circumstances and sustained critical head trauma.

TMZ reported Wednesday that Jeff Sperbeck was placed on life support after sustaining a traumatic brain injury, with doctors able to keep him alive only long enough to facilitate organ donation. The outlet also noted that it was John Elway who made the initial 911 call following Sperbeck’s fall from the golf cart.

The 64-year-old NFL legend and former Denver Broncos general manager, John Elway, was not only longtime friends with Jeff Sperbeck but also his business partner. Sperbeck had represented Elway throughout his professional playing career. Their professional relationship began in 1990 when Sperbeck became Elway’s agent during his NFL career. Over the years, their bond evolved into a deep friendship and successful business collaboration.

According to local news outlet KESQ, the two were at The Madison Club in La Quinta, California, on Saturday night when the incident occurred. Witnesses reported that Elway was driving the golf cart and Sperbeck had been riding on the back when he suddenly fell off.

The Riverside County Sheriff’s Office has since launched an investigation into the circumstances surrounding Sperbeck’s death, KESQ reported. PEOPLE has reached out to the department for additional comment.

Together, Elway and Sperbeck, co-founded the winery 7Cellars, combining their passion for excellence with a love of fine wine. Sperbeck also played a key role in helping Elway establish several restaurants under his name, further expanding the Hall of Famer’s post-football ventures. Known for his savvy negotiation skills and strong client relationships, Sperbeck represented more than 100 NFL players throughout his career. Elway, a two-time Super Bowl champion and former Denver Broncos general manager, remained closely tied to Sperbeck both personally and professionally.