Derek Hough too sick to go ‘Dancing’

Derek Hough is out.

The professional dancer will not compete with his celebrity partner, Joanna Krupa, on Monday night’s “Dancing With the Stars,” a rep for ABC confirmed to Access Hollywood.

Hough was forced out of the ballroom temporarily after coming down with the flu, something he tweeted about last week. And during a phone interview with Access Hollywood’s Billy Bush for “The Billy Bush Show” on Monday, Kelly Osbourne said they aren’t sure what kind of flu Hough has.

“They didn’t say if it was swine flu, but it could be they said,” Osbourne said.

And Hough isn’t the only one ill on the ABC reality show set. His friend Mark Ballas (paired with Melissa Joan Hart) is also feeling unwell.

“Derek is sick, Mark is sick, but it hit Derek really hard,” Osbourne said, noting Ballas is well enough to hit the ballroom tonight. “(Derek) had to go for IV because he got dehydrated … He came to rehearsal yesterday so everyone saw him, but I think it just really threw him. He didn’t expect it.”

Maksim Chmerkovskiy, who stepped in last week to help Joanna Krupa learn her dances for this evening, will compete in Hough’s place.

While illness is now ripe on the “DWTS” set, Osbourne thinks she and her professional partner, Louis van Amstel, will be fine.

“Louis and I are both very clean people so I’ve never worried that he was going to get sick and he’s never worried that I was going to get sick,” Osbourne said. “And we’ve been going to get B12 shots and stuff, so hopefully we’ll be fine. Fingers crossed.”

What Osbourne is worried about, however, is tonight’s dance, which is taking on an extra special significance.

“Today I’m going to be doing a paso doble which I’m really, really scared about because they gave me one of my dad’s songs to perform it to and I just hope I can do it justice because it’s scary,” Osbourne said, revealing her music will be Ozzy Osbourne’s “Crazy Train.”

“They did my hair exactly the same as my dad’s in the music video,” she continued. “So every time I’m walking (around) backstage everyone keeps laughing at me.”

Osbourne said her dad is likely to be in the audience to watch his little girl on the dance floor and she revealed the standing ovation she received from her parents during week 1 of competition was priceless.

“I think that will go down in my little history book of being one of the most amazing days of my life,” she said. “It was incredible.”