LOUDON, NH - SEPTEMBER 24: Denny Hamlin, driver of the #11 FedEx Ground Toyota, and Kyle Busch, driver of the #18 M&M's Caramel Toyota, wave to fans during pre-race ceremonies for the Monster Energy NASCAR Cup Series ISM Connect 300 at New Hampshire Motor Speedway on September 24, 2017 in Loudon, New Hampshire. (Photo by Chris Graythen/Getty Images)

One championship contender said there was a time he couldn't stand Kyle Busch

By now, every NASCAR fan is aware of the rivalry between Kyle Busch and Brad Keselowski. In summation, the two drivers don't like each. But Keselowski isn't the only driver in the Championship 4 who has been on bad terms with Busch in the past.

Kevin Harvick admitted he and Busch didn't like each other very much in the past, but the two drivers are on better terms now.

According to ESPN's Bob Pockrass, Kevin Harvick Inc. client Harrison Burton driver trucks for Busch's team, so the two Cup drivers have learned to work together to an extent.

"You have to look at things in life in general and sometimes you're like, 'Man, that's a waste of time,'" Harvick said. "I respect really all three of them (Busch, Martin Truex Jr., Keselowski). I respect Kyle just for everything he does in a racecar and I like racing with Kyle.

"And I have to deal with Kyle. Not personally, but through our office with Harrison (Burton). So, we have to have a working relationship as well."

Related: Kyle Busch makes loud and clear that he just can't stand this one rival

Busch said he and Harvick were joking around "like high school buddies" during some of their press appearances throughout the week.

"I guess we've grown to respect one another and what each other's done and where we've been the last 10 years with one another," Busch said. "I think that's just a matter of evolution of us growing up."

Despite Harvick and Busch's mutual respect, don't expect the same from Busch and Keselowski. Keselowski has attempted to be on better terms with Busch, but Busch said he really just doesn't like Kes.

So, while one rivalry has improved with Busch, he still has another major one lingering. Busch, Harvick, Keselowski and Truex will compete for the championship on Sunday afternoon at Homestead.