Jim Irsay -- Colts Owner Checks Into Treatment Facility ... After DUI Arrest

Indianapolis Colts owner Jim Irsay checked into a "highly-respected health care facility" ... one day after he was arrested for DUI and drug possession in Indiana.

A rep for the Colts tells TMZ Sports, "Yesterday, Jim Irsay took the first step toward regaining good health. He voluntarily checked into a highly-respected health care facility and is committed to undergoing the treatment and care necessary to help him meet his challenges head-on."

The Colts did not go into detail on the nature of the "challenges" Irsay faces ... but the 54-year-old has previously acknowledged his issues with substance abuse.

The Colts rep adds ... "Jim, the Irsay family, and the Colts organization are all deeply appreciative of the incredible outpouring of support and compassion from our fans and the Indiana community."

As we previously reported, Irsay was pulled over late Sunday night for traffic violations -- and during the stop, officers determined he was intoxicated ... though police have not said if he was drunk or high.

Cops did say Irsay was in possession of various prescription drugs -- but the pills didn't match the prescription bottles.