Former Springbok Aphiwe Dyantyi and flanker Kuyenzeka 'Nama' Xaba have both penned two-year deals with the Bulls.
Friday evening's clash between the Ospreys and Sharks at the Twickenham Stoop will mark the first time a United Rugby Championship fixture takes place in England.
Three of the four South African teams are on overseas duty for the second week of the United Rugby Championship, with some tough fixtures awaiting them.
Sharks coach Joey Mongalo is confident new signing Aphiwe Dyantyi will thrive under the leadership of the Durban-based franchise.
South Africa's Director of Rugby Rassie Erasmus says everyone deserves a second chance in life, which is why he would not rule out Aphiwe Dyantyi from being selected for the Springboks again.
Former Springbok and Lions star Aphiwe Dyantyi has signed for the Sharks as he looks to return to rugby after a four-year absence.