It follows an injury that occurred last Friday, forcing her to alter Saturday night's routine.
The performer then ended up in the dance off but with the injury worsened, it was decided she could not perform.
As a result, the elimination decision between Anastacia and Melvin Odoom reverted to the public vote. With the fewest votes, Melvin was eliminated.
It's been revealed today that Anastacia and pro dance partner Brendan Cole have been to see doctors and they've given her the all clear to perform this Saturday.
However again the pair will have to reduce their routine and work around Anastacia's injury.
The singer explained on Sunday's show how she had ripped scar issue on her chest from a double mastectomy.
A spokesperson for Anastacia told DigitalSpy this afternoon: "Yesterday, Anastacia visited the clinic of a specialist in breast reconstruction surgery. The doctor again confirmed that there was a tear in the scar tissue, which although painful is not permanent.
"She was given the all-clear to dance this weekend with the caveat that the routine is carefully choreographed and she has been given the appropriate medication. Brendan was with her for her appointments and they have been filmed for this weekend's episode.
"The specialist will be monitoring her condition regularly, and she will revisit them on Monday.
"She is doing this to raise money for breast cancer, so unless a doctor tells her she can't carry on, quitting would never be an option. Anastacia and Brendan are now in rehearsal."
A rep for the BBC added: "Anastacia is rehearsing her Viennese Waltz and is planning to perform it with Brendan on the show this Saturday."
This weekend will see Strictly head to the movies with the first theme week of the series.
But again on Sunday night one more celeb will go, with Anastacia made the favourite to leave by the bookies.