But that's nothing compared to the score he racked up the previous week -- .142 blood alcohol content, following a hit-and-run crash in which he was accompanied by an employee at Shotgun Willie's, one of Denver's most renowned strip clubs.
The incident reportedly took place about 3 a.m. on August 2. Four witnesses told Greenwood Village police officers they saw a purple Chevrolet Trailblazer smack a car in the parking lot of a Hyatt complex.
The driver quickly dismounted, but instead of checking out the damage, he split for the hotel lobby -- where officers subsequently found a 22-year-old woman who works at Shotgun Willie's. She told the cops she'd been riding in the Trailblazer with someone named "Matt P" -- but rather than stay with her at the Hyatt, he split, leaving her there.
He also abandoned the Trailblazer, a rental vehicle with a parking permit from the Broncos training facility sporting Prater's name. Also inside -- a duffel bag full of footballs.
At that point, the police began searching for Prater -- and they found him at a nearby La Quinta. He insisted that he hadn't consumed any liquor since 7 p.m. the evening before, yet the police report says he had booze on his breath and bloodshot eyes, and fumbled throughout a field sobriety test.
The report quotes Prater as saying, "I really messed up... I'm going to lose my job" -- and that's certainly possible. After all, the team is still reeling from the bad publicity stirred by former cornerback Perrish Cox, charged with fathering the child of a rape victim. Then again, Prater's crime is considerably less serious, and he's among the steadier performers on a team full of liabilities -- on the field, anyway.
The Broncos' statement: "Our organization is disappointed with the poor judgment shown by Matt Prater on Aug. 2. This matter, which was addressed with the team last week, continues to be thoroughly reviewed internally."
Below, take a larger look at Prater's mug shot, followed by a CBS4 report:
More from our Colorado Crimes archive: "Brandon Mondragon does less time in jail than his hit-&-run victim, Tim Albo, spent in rehab."