Hugo Broos' side will be facing a co-hosting nation for the second time in the tournament following their disappointing opening day 2-0 loss to Mexico.
However, Bafana have rallied since then to draw against the Czechia and produce a victory against the more fancied South Korea to progress to the knockout rounds.
"I think we don't have to disrespect them," said Khumalo to SABC3.
"We've played; we've been there to play a host nation. Ronwen [Williams] pointed out that maybe it was nerves [vs Mexico], boys were not themselves, the crowd [got to them].
"But they've played against Mexico and they are going to play against Canada now and I'd like believe that they cannot fault after what they've gone through, after what they've done because they are the only ones that can spoil it."
The 1996 African Cup of Nations winner also advised the players to attempt to be brave and play to their strengths in order to advance to the Round of 16.
"It's just for us to rally behind them and whatever Canada possess, whatever Canada plays we will be there and dish a South African way," added the 59-year-old.
"So, I don’t like going to a country or to a team worrying about them, they must also worry about us."
Kick-off is at 21H00 (SA time).
