Roberta O'Neill. 2008 Tucson Citizen photo

UPDATE: 12:05 p.m.: Yahoo! Sports: O’Neill apologizes for confrontation

UPDATE: 11:50 a.m.: Arizona athletic director Greg Byrne tweets that: “U of Arizona is aware of the situation from last night and we know that the conference and USC is looking into the incident.”

The subplot for tonight’s Pac-10 tournament semifinal between USC and Arizona has changed.

It’s not just a Trojans team desperate for a victory as it pushes for the NCAA Tournament. It’s not just Arizona, the regular-season Pac-10 champion, trying to improve its seeding for the NCAA.

Now, it’s back to the whole Kevin O’Neill mess.

USC athletic director Pat Haden released a statement Thursday night in response to a postgame incident involving O’Neill:

“We have received some information tonight about an incident involving coach Kevin O’Neill, his wife and a fan from another school that occurred following our men’s basketball game today.

“We are looking into this and gathering facts. We will determine what appropriate action is necessary.”

The popular sports website, The Big Lead, posted the story this morning, with editor-in-chief Jason McIntyre tweeting that he had “Just called the Arizona donor who got hit by Kevin O’Neill’s wife. I interrupted his breakfast. He was nice about it (he’s about 70).”

The Big Lead also has linked a story on O’Neill’s wife, Roberta, that I wrote for the print edition of the Tucson Citizen three years ago.

O’Neill was deemed the villain for the unhappy 2007-08 season at Arizona, when he was thrust into the interim head coaching position when Lute Olson took an unexplained leave of absence. During the season, then-athletic director Jim Livengood made O’Neill the head-coach-in-waiting for whenever Olson decided to officially retire.

Kevin O'Neill has always been known for his fiery behavior. Photo by Jeff Gross/Getty Images

It was a messy time for everyone. Nobody around the program really knew what was going on or where to pledge allegiances. My take on it: O’Neill didn’t create the mess, but he didn’t help it, either. He was the wrong guy at the wrong time, and he had the misfortune of navigating the toughest Pac-10 in history.

Olson did return after the season, and pushed O’Neill out.

No doubt, O’Neill has been the target of Arizona fans’ venom, and that likely contributed to whatever happened Thursday night.

My guess is that O’Neill has some Arizona stories that he has kept to himself in the past few years. But Kevin is Kevin, which means he has a hard time keeping his mouth shut.

There were festering issues this season, such as the pointing incident and the verbal swipe between him and UA senior Jamelle Horne.

And there was O’Neill’s claim that Arizona sophomore Derrick Williams received favorable treatment from Pac-10 officials.

And now this.

Should make for an even more interesting Friday night.