Sharks coach John Plumtree says wing JP Pietersen is likely to miss the rest of the Super 14 with a knee injury.
Plumtree said Tuesday "it doesn't look good" for the Springboks player, who limped off after 20 minutes of the Sharks' 23-10 win over the Auckland Blues in Durban this weekend.
Plumtree said Pietersen appears to have a cartilage tear and "will probably be out for the rest of the tournament."
Plumtree's team face a crucial match against South African rival and defending champion the Bulls in Pretoria this Saturday.
The Sharks need to win all their remaining games to have a chance at qualifying for the semifinals.
Standings leader the Bulls have won 16 successive games at their Loftus Versfeld stadium.
