Covid-19 has robbed 2019 World Rugby Player of the Year Pieter-Steph du Toit of a farewell home appearance for the Stormers in Cape Town on Saturday.
A Rainbow Cup SA final round match against the Lions was called off after an unspecified number of players from the Johannesburg franchise contracted the illness.
Stormers' officials confirmed that the Springbok flanker is leaving them to play for Toyota Verblitz, a Japanese club guided by former All Blacks coach Steve Hansen.
What the 28-year-old, who has been capped 55 times by South Africa, intends doing after the six-month contract expires next May has not been disclosed.
Du Toit is set to play for the Springboks against Georgia, the British and Irish Lions, in the Rugby Championship and on a tour of Europe before travelling to Japan in November.
Two other South Africans - fullback Willie le Roux and utility forward Jason Jenkins - are with the Japanese Top League outfit.
A key figure when South Africa won the 2019 Rugby World Cup in Japan, Du Toit suffered a thigh injury in a Super Rugby match last year that almost ended his career.
The rapid reactions of medical staff at Newlands saved the star from having a leg amputated.