The professional, who had been teamed with former home secretary Jacqui Smith, now eliminated, has long been touted as a possible contender to join the judges full time.
Bruno Tonioli is already absent from the panel as he is unable to travel back from the US while filming Dancing With The Stars in Los Angeles.
A statement from the programme said: “We are pleased to announce that the King of Ballroom Anton du Beke is stepping into our judging panel this weekend. Good luck Anton!”
Mabuse sent her congratulations to du Beke on Twitter, writing: “Congratulations!! All the best. I know you will be amazing.
“Enjoy this season guys and remember #strictlykindness.”
On Thursday Mabuse, who was born in South Africa but lives in Germany, wrote on Twitter: “Earlier this week I needed to travel to Germany for an urgent reason.
“I will of course be following the UK Government guidelines and self-isolating for 14 days.
“I’ll be watching from home and by the power of technology, should be in your living rooms. Watch out though, I’ll be doing my own hair and make-up.”
According to current guidelines, travellers arriving in the UK from Germany must self-isolate for 14 days.
It came hours after Olympic boxer Nicola Adams and her partner Katya Jones were forced to leave the competition after the professional dancer tested positive for coronavirus.
And earlier in the day Rylan Clark-Neal, co-host of Strictly spin-off It Takes Two, announced he was self-isolating after coming into contact with someone outside of work who tested positive.
Adams, 38, and Russian dancer Jones, 31, are currently self-isolating separately after Jones received a positive test while asymptomatic.
They made history this series as the BBC One show’s first same-sex couple.
Tonioli is making appearances via video link on the Sunday evening shows and is expected to return later during the series.