If anyone knows how hard it is to bow out from an injury it's Shawn Johnson.

In June, the 20-year-old announced a knee injury would end her Olympic gymnastics career. Right after that announcement, she was asked to do Dancing With the Stars All-Stars. She was paired with Derek Hough, who just announced on the Week 6 Results Show that he would have to sit out the upcoming Week 7 due to his own revived injury. (He’s had a bulging disc in his vertebrae for a couple of years and it became inflamed this week.)

"Losing Derek today was heart-wrenching," Shawn told Zap2it. Her Season 8 partner Mark Ballas will be stepping in to work with her this week, but Shawn said he's just going to do the movements; Derek is still going to be in all the rehearsals helping choreograph and making sure it's under his control — in case he does step back in on Monday. "I know if he's not dancing on Monday, he'll be dancing next week for sure," Shawn said.

Shawn told On the Red Carpet she's very comfortable with Mark, so it won't be a tough transition, but she'll be preoccupied with her worry for Derek. "Having been through injury and pain, I know what he's going through and it kills me to know that I can't do anything." Shawn will also be presenting at the CMAs tomorrow and Mark will be going with her instead of Derek, so they can get some practice sessions in.

It's good that Shawn has such a great support system in her two DWTS pros — who happen to be best friends — but this is obviously not the ideal situation. Get well soon, Derek!

Catch a new episode of Dancing With the Stars Season 15: All-Stars on Monday, November 5 at 8 p.m. ET/PT on ABC.

Sources: Zap2it, On the Red Carpet

Gina Carbone is a contributing writer at Wetpaint Entertainment. Follow her on Twitter @ginacarbone.

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