Transcript for Christie Brinkley’s daughter steps up on ‘DWTS’
An exclusive look behind the scenes of didn't ahead of tonight's premiere. We now know Christie Brinkley will not compete because of an injury. Her daughter stepping up in her place and ginger is there on the set and, ginger, you got to speak with sailor. I did. Sailor is such a special young woman. I can't wait for you all to see her dance but you heard that. An injury for Christie Brinkley. She broke her arm. We keep saying that. She actually shattered her arm, they told me. She had to have surgery. She is doing well this morning and recovering but she'll be watching just like the rest of us as her daughter hits this very dance floor tonight with a dance that she learned only two days ago. A jaw-dropping headline in the ballroom. One of the stars out before the competition even begins. We just found out that Christie Brinkley will not be hitting that dance floor. She broke her arm in rehearsals. And this is the moment it all happened. The executive producer talking to us backstage. She was rehearsing Thursday night and you do what everyone does, take your arm when you go down and immediately said I think I broke it. It's the nature of the show. You never know what's going to happen. You roll with the punches. If you were able to get a partner three days before, what is the difference? Ooh, probably going to stay away from lifts. Reporter: Her mystery partner now left with an extra challenge, teaching Christie's replacement, her daughter sailor a dance in just three days. I sat down with her exclusively. I mean, you got on a flight out here to support your mom. When you landed, they said, will you fill in for your mom? I'm literally about to take off and my mom calls me and said, sailor, you need to save the day. I was like, what do you mean save the day? I freaked out and I was like, I don't know if I can do this. I'm so scared and then I met with everyone from "Dancing with the stars" and my partner and it was -- I felt this high of like just attacking something that I'm so afraid of seemed so incredible to do. She cries every five minutes at the fact that I'm doing this and taking over and it's basically she always calls it the silver we found the silver lining in a terrible situation. And you're it. And I'm it, I guess. Christie telling ABC news showbiz is all about getting a break and sailor and I both got one on "Dancing with the stars" this season. Sailor joined the cast when I got mine, ouch, somebody stop me, it hurts to laugh. As for the judges, they don't care who is on the dance floor, as long as the dancing is good. Sailor has jumped in for her With three days' practice. That's very little. That is very, very little. Do you take that into account at all. No, I'm not. I'm not taking anything into account. I'm gunning for people this year. Grumpy old Len. Sailor, though, truly is a mini-me. She radiates beauty just like her mother but it's the humility, the grace I can already see in her and the danceability that I think has a chance of going really far in this competition and just to note, sailor, the wardrobe, you know, all tailored perfectly to Christie Brinkley's body. Sailor dropped right in. It fit her perfectly so it's going to be a beautiful night. What's it feel like being back on that dance floor, ginger for you. Good every time, every time. I thought you were going to hit the new Yorker for us. That little new Yorker thing. Yes. Yes. I know that. I know. Great to see you there, "Dancing with the stars" premieres tonight at 8:00. She is still dancing right here on ABC.
This transcript has been automatically generated and may not be 100% accurate.