South Africa left-arm spinner Nicky Boje is in doubt for next month's tour of Australia, after suffering a recurrence of a knee injury.

"I fell on my right knee during the second Test (against India) in Port Elizabeth last week," Boje said.

"I'm not too worried at this stage but I'm going to Cape Town to see a specialist on Wednesday and then we will assess the situation.

"It is the same injury that I have struggled with before."

The United Cricket Board of South Africa (UCBSA) confirmed that they had put Western Province left-arm spinner Claude Henderson on standby.

"He might have to undergo a fitness test as a precaution," the UCB's Bronwyn Wilkinson said.

"We have placed Claude Henderson on standby for the tour."

Henderson played two Test matches against Zimbabwe in September.