Cape Town - The Sharks are sweating on the fitness of captain Patrick Lambie, loose forward Philip van der Walt and fullback Clement Poitrenaud following their impressive 37-14 win over the Waratahs in Durban on Saturday night.
Van der Walt left the field with around 15 minutes remaining with a head knock.
"He's gone to the hospital now to be checked out properly and we hope and pray that he will be good," coach Robert du Preez said.
The big concern, though, is Lambie.
Having been injury-prone for the past three Super Rugby seasons, the Springbok and Sharks flyhalf lasted just five minutes in Saturday's clash before he was forced off with what was later confirmed to be a back injury.
"Pat hurt his back. He got tackled and fell on his back," Du Preez said.
"I'm not too sure (how bad the injury is). It's not great coming off... he's a tough guy. Hopefully it's not too serious."
Lambie's exit meant that 19-year-old Curwin Bosch was given the flyhalf duties for the evening, and he was hugely impressive, scoring 27 points on the night.
"He's talented. He had a good game," said Du Preez.
"We obviously practice him in at 10, but it's not the same. He's been playing fullback since last year."
The other concern for Du Preez comes in the form of Clement Poitrenaud, who left the field just after half-time with a groin injury.
The Sharks are expected to provide more clarity on their injuries on Monday.
They are next in action when they host the Kings this coming Saturday.