Vermeulen limped off the park on Friday evening during the Bulls 31-27 win over the Stormers at Loftus Versfeld.

Vermeulen has headed to Cape Town in order to consult a specialist.

The Director of the Rugby, Rassie Erasmus, conceded they are concerned over the World Cup winner.

“We know that South African derbies can be brutal and so far, we've actually been lucky.

“If you look at what happened in Super Rugby Aotearoa and you look at all of those injuries. Sam Cane, Jack Goodhue, they have a massive number of players.

“We will have to wait and see, but it certainly looked bad, and he wouldn’t have limped off if it wasn’t serious, so we are unfortunately fearing for the worst.

“We always expected that with the Rainbow Cup being strength versus strength we could have some injury setbacks.

“Up until now, we have been quite fortunate with injuries, touch wood, but we did expect some big losses and I expect Duane might be one of them.”

Should Vermeulen not be declared fit it will open the door for the former Cheetah, Jasper Wiese, to make his Springbok debut.

@MorganPiek OFM Sport