Actress Natalie, who is partnered with Artem Chigvintsev on the BBC1 show, reportedly had an MRI scan yesterday (16 October) after it was thought she slipped a disc.
The dancing hopeful missed training and is now waiting to find out whether medics think she will be ok to perform on Saturday night - or whether she needs to hang up her ballroom shoes.
Last weekend, Natalie was top of the leader board again after receiving an impressive score of 36 for her rhumba.
Speaking about Natalie's painful injury, Artem has been quoted saying: "We had to finish rehearsal early on Tuesday because of the pain in Natalie's back - if it is serious she might not be able to continue."
It has been reported that Natalie may have aggravated an old back injury following a fall during rehearsals.
Get well soon, Natalie, we have our fingers crossed for you.