Strictly Come Dancing professional Artem Chigvintsev has been forced to take a break from the show after fracturing his spine.
The 29-year-old was diagnosed with a transverse process fracture of the lumbar spine after injuring himself while rehearsing with Holly Valance last Friday (November 4).
"Artem injured himself during rehearsals on Friday," the BBC confirmed. "Following medical attention he has been diagnosed with a transverse process fracture of the lumbar spine.
"We have been told that this sort of fracture is completely stable and he has been advised that there is no untoward effect from him continuing to dance. We will, of course, continue to review this following medical advice over the course of the week."
Valance is currently training with Brendan Cole, who left the competition along with his partner Lulu on Sunday (November 6), and could perform with the 35-year-old on this week's show.
"At the moment, Artem is not dancing - but he is attending rehearsals and choreographing the new routine," a BBC source said. "He wants to dance, but his health is our priority. We have a duty of care to him."
Another insider commented: "Heaven knows how Artem's going to dance on Saturday. This is a serious injury."
Chigvintsev's condition, caused by extreme rotation or sideways bending, had originally been misdiagnosed as a strained muscle.
The Russian pro won last year's series of Strictly Come Dancing with his now-girlfriend Kara Tointon.
It was previously reported that Tointon had grown jealous of Chigvintsev's passionate performances with Valance, though the women are apparently now on good terms and "text every day".