Derek Hough was forced to miss a group rehearsal for Dancing With The Stars after becoming violently ill with the flu on Thursday.

Oh dear, we hope it isn’t swine flu!

“Woke up with the seirous sweats,” the former DWTS champ Tweeted early yesterday. “I think I’m getting the flew … Had a bath now trying to get more sleep.”

“Bummer,” Derek continued. “Tough week.”

According to his Dancing partner, Joanna Krupa, also had a big fever.

“poor derek has a 104 temp so he ll need to rest so he can get better soon,” she Tweeted.

Derek’s condition worsened as Thursday morning turned to afternoon.

“My whole body is aching like crazy,” Derek wrote. “I can barely stand up … And I’m coughing like crazy.. This sucks “

While Derek recovers, Maksim Chmerkovskiy — who was voted off Season 9 with partner Debi Mazar two weeks — is helping Joanna learn her dance moves for next week:

“At the docs for 3 hrs today … Had a temprature of 104 … Had an IV in my arm for 2hrs … Maks is steppin up for me helpin jo…”

It’ll be interesting to see how that turns out since it’s well-documented that Maks and Joanna hate each other.

“i havent gotten any updates from derek how he is doing,” Joanna Tweeted Thursday evening. “my rehearsals with maks arent until later this evening. loooong day.”

Best wishes for a speedy recovery for Derek…