A source tells ET they're "not sure yet" if Skarlatos' nose is officially broken, but it is definitely injured. An ambulance was called to rehearsals and the 23-year-old is currently at a doctor's office.
However, Skarlatos' rep tells ET that he will be performing in tonight's show and the official diagnosis is expected tomorrow.
Just before the injury, Slater posted a happy photo of the dancing duo on Instagram with the caption, "Thank you for being my partner this week Alek Skarlatos, I'm so excited for our dance today!"
This dancing mishap comes just days after his pal Spencer Stone was stabbed multiple times last week during a fight outside a Sacramento, California night club.
Skarlatos took time away from his DWTS rehearsals on Saturday to snap a selfie with Spencer at his bedside at UC Davis Medical Center, and captioned the pic: "Saw the hero today." He later took down the image.
The men are two of the three American heroes that helped take down a gunman on a Paris-bound train from Amsterdam in August.
Dancing With the Stars airs tonight at 8 p.m. on ABC.