San Francisco offensive guard Thomas Herrion passed away early Sunday morning following Saturday night's preseason game with the Denver Broncos.
Herrion collapsed in the locker room moments after the game, was given CPR and rushed to St. Anthony's Central Hospital in Denver. He was pronounced dead three hours later.
"This is a colossal tragedy for the 49ers and the entire NFL community, the team said on their official website.
"We still do not know all of the details. However, our thoughts and prayers are with the entire Herrion family."
Herrion was a first-year player with San Francisco after playing college ball at Utah. He spent part of last season on the San Francisco and Dallas practice squads and also played this season with the Hamburg Sea Dogs of NFL Europe.
The cause of death has yet to be determined.
Herrion was 23 years old.
49ers offensive lineman dies following game
Mile High Huddle Top Stories
Interpreting Elway's Comments About RomoWith the NFL Owners' meeting underway, Broncos GM John Elway was asked about the Tony Romo situation. His response was intriguing.
Mile High HuddleYesterday at 4:05 PM
Denver's Biggest Needs Heading Into The DraftMore than two weeks out from the opening bell of free agency, the Broncos still have some big roster needs.
Mile High HuddleSunday at 2:00 PM
Could A Romo Resolution Come This Weekend?With the NFL Owner's Meetings on the schedule this weekend, could we finally see a resolution to Romo Watch?
Mile High HuddleSaturday at 2:42 PM
How Denver's Free Agent Haul Bolstered O-LineThe Broncos committed significant resources in free agency to bolster the offensive trenches. One of Denver's leading O-line analysts, Doc Bear, breaks down the free agent…
Mile High HuddleSaturday at 9:46 AM