Donte Stallworth -- Jim Irsay's Arrest Is Blessing In Disguise

Jim Irsay's DUI arrest could be the best thing that ever happened to the Colts owner ... so says ex-NFL star Donte Stallworth who tells TMZ Sports he has an opportunity to change his life BEFORE it's too late.

Donte knows what he's talking about ... 5 years ago, he killed 59-year-old Mario Reyes in a drunk driving accident in Florida and says he still lives with tremendous regret from the incident.

"Hopefully, [Jim] can look at the unfortunate decision I made, and learn from it," Stallworth says ... "He's lucky it wasn't more serious."

Donte says he's happy Jim has checked himself into treatment -- "It’s good he's going to get some help. The first step is admitting you need it."

"I've talked with people who lost family members to drunk driving. They come up to me randomly. It's a constant reminder of the decision I made" "

Donte recently tweeted about the lessons he's learning -- saying, "There’s nothing I can do to reverse that day, but hopefully you guys will think of me and make better decisions than I did that morning. You don’t want to live with these regrets I have from my irrevocable decision… Trust me."