The judge posted a message on Twitter saying she was “gutted” about missing the shows but said “our health is the most important thing”.
The BBC show has confirmed that Cynthia Erivo will be filling in as a guest judge.
Mabuse, who lives in Germany, wrote on Twitter: “I am gutted to say I will have to miss this weekend on Strictly... yesterday I was contacted by NHS Test and Trace as being in close contact with someone on Sunday 21st Nov who has since tested positive.
"Being double vaccinated and booster as I am, would normally mean exemption from isolation under the ‘close contact’ rules, but unfortunately German EU vaccines are not recognised and neither is my booster in this instance – so I must follow UK Government Guidance and can only return after 30 November 2021 to UK.
"Our health is the most important thing and luckily I have been tested multiple times this week and am negative.
"I am healthy, I am with my family, that’s what matters. I wish everyone good luck, sending you my love, keep dancing."
"Until then, lots of love and stay safe," added the star.
As Motsi will not be taking part in #Strictly this weekend, we are delighted that Cynthia Erivo will be joining us as a guest Judge again! We look forward to having Motsi back in the Ballroom next week. #Strictly pic.twitter.com/XVD15y5TO2
— BBC Strictly ✨ (@bbcstrictly) November 26, 2021
A Strictly spokesperson said: "We can confirm Motsi Mabuse will not be taking part in Strictly Come Dancing this weekend.
“We are delighted that Cynthia Erivo will be joining us as a guest judge again, joining Craig Revel Horwood, Anton Du Beke and Head Judge, Shirley Ballas on the judging panel.
“We look forward to having Motsi back with us next weekend.”
Watch: Anton Du Beke 'so delighted' to become Strictly Come Dancing judge