John Elway 'Devastated & Heartbroken' Over Agent Jeff Sperbeck's Death

John Elway's breaking his silence over the death of his longtime agent and best friend ... saying he's absolutely crushed over the tragedy.

“I am absolutely devastated and heartbroken by the passing of my close friend, business partner and agent Jeff Sperbeck. There are no words to truly express the profound sadness I feel with the sudden loss of someone who has meant so much to me," the 2x Super Bowl winner wrote.

Elway continued ... "My heart and deepest sympathies go out to Jeff’s wife, Cori; his children Carly, Sam and Jackson; and everyone who knew and loved him. Jeff will be deeply missed for the loyalty, wisdom, friendship and love he brought into my life and the lives of so many others.”

TMZ Sports broke the story earlier this week. John and Jeff, along with several of their family members, were leaving a post-Stagecoach party on Saturday around 7 PM when Sperbeck fell off of a golf cart that was driven by the Hall of Fame quarterback.

Jeff hit his head on the ground, suffering a traumatic brain injury.

Elway immediately called 911 ... but despite the medics and doctors' best efforts, John's partner and friend couldn't be saved.

Doctors kept the 62-year-old on life support until his organs could be harvested for donation.

Sperbeck was pronounced dead at 1:10 AM Wednesday morning.