Derek Hough's illness has him on the sideline for Dancing with the Stars' rehearsals.

Hough has temporarily left Dancing with the Stars' ninth season due to flu-like symptoms and his celebrity partner Joanna Krupa will work with recently eliminated professional Maksim Chmerkovskiy during rehearsals, sources told Us Weekly in a Friday report.

It has yet-to-be determined who will be Krupa's partner during Monday night's live performance episode broadcast, Us reported.

Hough first addressed his illness in a Thursday post on his Twitter account.

"Woke up with the seirous sweats .. I think I'm getting the flew ... Had a bath now trying to get more sleep ... Bummer .. Tough week," he wrote before providing an update on Thursday night.

"My whole body is aching like crazy I can barely stand up ... And I'm coughing like crazy.. This sucks .. 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 .. Hopefully I will feel better tomorrow ... Fingers crossed ..."

Hough subsequently wrote he was "feeling a little better" on Friday and he spent the weekend recovering before going outside for the first time in three days on Sunday.

"It sucks being alone, especially when your sick," he wrote on Sunday.  "Saw Joanna and Maks dance today, really proud of her ... And Maks did a great job with her ... If she went home this week. I would totally Blame myself, please vote."

Chmerkovskiy and his ninth-season celebrity partner Debi Mazar were eliminated from the competition two weeks ago.