Everyone got a little muddy when Brad Underwood bolted to Illini

If you wade into the sludge of big-time college sports, you’re going to get dirty. This applies not just to coaches and athletes, but to fans as well. The only question is whether washing your hands will do the trick or whether a decontamination shower will be necessary.

Illinois fans are excited about the school’s hiring of Brad Underwood as its basketball coach, and they should be. He has had a successful career.

Oklahoma State fans are angry with Underwood for leaving them after just one season, and they should be. He publicly declared his fealty to the school when it hired him a year ago.

In college sports, your cad is somebody else’s hero.

Here’s what one Oklahoma State fan told the Oklahoman newspaper after Underwood left unexpectedly for Illinois this week:

“It kind of feels like you got duped by a used-car salesman as you hear the things in his Illinois news conference sound just like the things he said a year ago. You start to think it’s just all words.”

Wait, what? A used-car salesman? The guy who was greeted in Champaign on Monday as if he were a cross between John Wooden and Abe Lincoln? How can this be?

Illinois offered Underwood a six-year contract averaging $3 million a year, and Oklahoma State reportedly offered $2.2 million a year. So he left. He wanted more money, and his employer didn’t want to go higher. OK, understandable. There might have been friction with the athletic director. Again, fine. But Underwood is the same guy who swore he loved Oklahoma State to death, wanted to build a winner there and all but hoped to die a Cowboy.

How much for that 2002 Buick Regal?

Underwood called Illinois a “dream job’’ at his introductory news conference in Champaign on Monday, a statement that, wait a second, sounds very familiar.

“A dream come true,’’ Underwood said of the Oklahoma State job at his introductory news conference in Stillwater, Okla., a year ago.

There are two sets of fans who should feel a little dirtier today than they did a week ago.

The sleaziness usually starts bubbling up when coaches feel the need to sell themselves as something they almost certainly are not. Most of these people aren’t loyal, but you’d think they were admirals vowing to go down with their ships when they start waxing poetic about how much their school means to them. Eventually, though, college coaches either abandon ship or are told to walk the plank. It’s why, if you ever mail a letter to a coach, you should always address it to Current Resident.

It’s hard to begrudge someone for wanting to make more money. But when that person has told everyone of his deep love for a school and then bolts like Usain Bolt, it’s very easy to begrudge him. You’d also like to bludgeon him.

I’m sure Underwood sold his vision of Oklahoma State to talented high school basketball players around the country. It probably looked a lot like heaven. I’m also sure that Underwood has called some of former Illini coach John Groce’s recruits to guarantee them he’ll be in Champaign for a long time. Because, you know, it’s heaven.

Coaches will argue that they have no choice but to be 100 percent pro-school while recruiting. They’re merely selling a product, they say, just like the guy at the appliance store is. But the coaches themselves are the product, and this is where the dirtiness comes in. The flesh-and-blood product is being sold to young adults, not world-wise people. Some of these kids end up picking the coach, not the school. Silly, I know.

A coach can leave for a better opportunity at another school, but a player can’t, not without having to sit out a year. And people wonder why college athletes want to unionize. Would Underwood have taken the Illinois job if there were a rule requiring coaches to sit out a year after leaving one job for another? Almost certainly not.

The flip side is that coaches get fired all the time. It’s a victory-based system set up for griminess.

Fans get hurt all the time. Illini fans were upset when Bill Self left for the Kansas job in 2003. And Northwestern fans probably won’t forget this 1997 declaration from football coach Gary Barnett after he had talked with UCLA, Georgia, Notre Dame, Texas and the Detroit Lions over the previous three years:

“I’m here, and I will be here for the next 10 years of my contract, and if Northwestern extends that contract, I will accept it.’’

In 1999, he left for Colorado.

Time for everybody to clean themselves up. Again.