Credit: Joe Kohen/WireImage

Following a painful back injury, Dancing With the Stars dance pro Derek Hough may not be dancing in the Monday, Oct. 28 episode of the hit ABC competition show. A sources tells Us Weekly that the Emmy-winning dancer needs to get medical clearance before hitting the dance floor this week.

His partner, Glee star Amber Riley, will dance with pro Henry Byalikov in tonight's episode if Hough is unable to lace up his shoes. "[Hough's] back is severely injured – he had a pre-existing injury," the source explains to Us. "He hurt his back dancing with Shawn Johnson [during Season 15 in late 2012], and he re-injured it dancing with Amber. He is determined to push through but not sure he'll be able to."

Yesterday Hough posted a photo on Twitter of what appears to be a doctor giving him injections into his back. 

"This is happening … Ouch!" the star captioned the photo. 

On Oct. 28, Amber Riley tweeted, "Dress rehearsal with #TeamFoxingAwesome," but did not indicate whether Hough was dancing with her. 

Derek is the older brother of dancer-turned actress Julianne Hough, 25, who was a dance pro on DWTS for five seasons and recently returned to the show as a controversial guest judge. Derek has been a dance pro for 12 seasons on the hit show and recently won an Emmy for his choreography.