Sharks will be without Willem Alberts for the start of their Super Rugby campaign after the forward underwent shoulder surgery on Tuesday.
The South Africa international, who has missed their last two pre-season friendlies, is expected to be out of action for at least four weeks.
According to officials from the club, he underwent the "small procedure" on Tuesday, and will therefore miss Saturday's opening match against the Cheetahs.
The 27-year-old has played the last nine internationals for his country.
