'DWTS: All-Stars' Tackle Week Eight Rehearsals

With seven couples left to duke it out for the coveted mirror ball trophy, the Dancing with the Stars: All-Stars competition is really heating up!

Related: 'DWTS' Pro Derek Hough Will Need Surgery

Melissa Rycroft, Apolo Anton Ohno and Shawn Johnson graciously let ETOnline in on their week eight rehearsals as the celebrities and their pro partners were immersed in preparation for Monday's Trio Challenge.

"Between [Derek Hough's] neck and my knee, it's pretty interesting to choreograph around," said Shawn who, earlier this year, was forced to drop out of the summer Olympics as the result of a skiing injury.

As if Shawn's knee didn't present enough of a challenge, Hough will soon have to undergo surgery for a herniated disc. The DWTS pro told ET that his injury has made things especially tough given what is expected of the samba, their assigned dance.

"There are so many head whips," cringed Derek.

Video: Shawn Johnson Upset over 'DWTS' Partner's Injury

Click the video for more from Shawn and Derek, including interviews with Melissa Rycroft, Apolo Anton Ohno and their pro partners.

Don't forget to tune in to ABC tonight for all the action! Plus, in honor of Veterans Day, the first round will feature performances to songs that pay homage to servicemen and women.