Strictly Come Dancingdancer Gorka Marquez was attacked by youths in the streets of Blackpool hours after he took part in a special episode of the show.
The 26-year-old had two of his teeth knocked out when he was set upon by a group of youths in the street.
It is believed he was attacked as he walked to a nightclub in the town.
He took part in Saturday’s live show in a group routine after being knocked out in the second round of the series.
Strictly travels to Blackpool once per series for a special episode broadcast from the home of ballroom dancing, the Winter Gardens Tower Ballroom.
The Spanish dancer had partnered EastEnders actress Tameka Empson, and later in the series stepped in to partner singer Anastacia when professional dancer Brendan Cole suffered from illness.
He is due to undergo dental surgery on Monday. However, he is expected to rejoin rehearsals later in the week.
A friend told the Sun: “Gorka’s an incredibly passive guy, he wouldn’t hurt a fly. He’s so upbeat that he won’t let an unprovoked attack from a yob ruin his first Strictly in Blackpool.”
A BBC spokesman said: “Gorka was sadly the victim of an unprovoked incident in Blackpool on Saturday night, but he will be back in training this week and is looking forward to the group routine next weekend.”
Greg Rutherford: Strictly is physically and mentally tiringPlay!01:00
On Sunday Olympic long jumper Greg Rutherford became the latest celebrity to leave the show.
He said it was “horrible” to be departing, after he lost out in the dance-off to gymnast Claudia Fragapane.
Rutherford scored 32 for his quickstep with partner Natalie Lowe.
Rutherford, who recently turned 30, said: “It’s horrible, I mean it’s something that completely engulfs your life and every aspect – I mean I am training 10 to 12 hours a day – I have been putting all my heart and soul into it.
“I would like to think I was getting better and improving but obviously not. It’s a very, very tough year this year, there are some exceptional dancers and I knew I was never as good as those guys but I was going to try as hard as I possibly could to get as close as I could.
“Sadly for me it’s finished now. I’m gutted. I spend all my time with Natalie at the moment, we have such a great partnership and such a great friendship that now I know on Monday morning I won’t be doing that now and that’s difficult.”