Credit: FOX

Ellen DeGeneres admits sharing the judging panel with American Idol's Simon Cowell will be a "challenge," but insists there's no bad blood between them.

"Everyone's making such a big deal of the tension, but there's been a lot of fun on that panel," DeGeneres, 52, told KIIS-FM's Ryan Seacrest Tuesday. "Kara [DioGuardi]'s been great, Randy [Jackson]'s been great."

As for Cowell?

"I think he's a funny guy," the talk show host, who makes her debut on Tuesday's show, says. "I like him on Wednesday['s show]. I like him on one day, I can't remember which. He's going to be a challenge. He's Simon and I'm me and we’re two different people. We'll see how it goes."

Reports surfaced in January that Cowell, 50, was already clashing with DeGeneres during the taping of the Hollywood Week audition rounds.

At her first taping, Cowell was more than an hour late because he had just confirmed he was leaving the show after this season -- and DeGeneres insisted that they begin without him.

"When Simon showed up, he was p**sy that they started without him," a source tells

But Cowell apologized, and DeGeneres "accepted it right away and was fine," adds the insider.

When it comes to dealing with the contestants, DeGeneres tells Seacrest she'll use humor.

"Yes, it's a show and I want it to be entertaining and I want to be funny, but at the same time, it's somebody's career," DeGeneres says. That's what's great about all four of us [judges] -- we couldn't be more different in style... I like a challenge, and this is going to be good."