Nastia Liukin may have to add a new name to her dance card next Monday night on "Dancing with the Stars."

Her pro dancing partner, Derek Hough, suffered multiple injuries while rehearsing for the 10th Anniversary "Dancing with the Stars" television special on April 20, his rep told E! News in a statement. He broke a toe on his right foot, sprained the inside and outside of his left ankle and bruised a bone on the same ankle.

In addition to his responsibilities on the ABC competition show, the 29-year-old dancer is also starring in the New York Spring Spectacular at Radio City Music Hall in New York City. He will remain in Los Angeles this week to rehab his injuries and his understudy, Taylor Frey, will fill in for him in New York opposite Laura Benanti.

Hough may be able to dance with Liukin on Monday night, but she will rehearse with pro dancer Sasha Farber to prepare for the live show. The dancing couple received the highest scores in weeks two and three, and tied with Willow Shields and Mark Ballas for the second highest this past week.

Ballas took his pal Hough to the emergency room on Monday night. He posted an Instagram photo of him pushing Hough in a wheelchair as they both gave the camera sad faces.

"I was with him until all hours of the night... Derek's an optimist," Ballas told E! News on Tuesday night. "He's always up and he's always bringing the people around him up. His energy is always positive."

Fellow pro Sharna Burgess believes that Hough's injury was a sign from the universe saying, "Derek you need to take a break," referring to his busy schedule. She does have full faith in Liukin's ability to soldier on with a new partner if needed, but compares changing partners to "changing a language."

"Nastia, my heart goes out to her, just passed midway in the season, having to change pros," she told E! News. "We build a language between each other on how we work with each other and that's what enables us to be able to do what we do every week with all the pressure and the stress, trying to do things that are unnatural for these people."

A photo posted by Derek Hough (@derekhough) on Apr 22, 2015 at 12:21pm PDT

Hough posted an Instagram photo of his feet bandaged up from the other night when he sat in the ER with Ballas and Ballas' girlfriend Britney Jean Carlson. In the photo's caption, the pro dancer claimed he usually works through injuries but this one has "literally floored him."

Before his accident, he was performing 10 shows a week at Radio City while rehearsing with Liukin for "DWTS."

"I've never felt more healthy, strong and fit. But then a fluke accident happened that involved a light and some stairs," he wrote on Wednesday afternoon. "Can't believe it, wish I had a cooler story to tell. All that dancing, flipping, jumping and the thing that stops me in my tracks is something as simple as light and some stairs. I'm doing everything I possibly can to have a quick recovery and I'm determined to come back strong than ever."

"Dancing with the Stars" airs on Mondays at 8 p.m. on ABC.