Scotland will face Bolivia for the first time but Clarke faces more questions about group rivals Haiti after beating New Zealand 4-0 on Tuesday.
He quickly highlighted that some fans have a “terrible habit of looking at these countries and thinking they’re not good enough or looking at where they are in the world.
“They play in a different section of the world, so maybe in their own section they’re really good,” Clarke said. “They were much better than New Zealand.
“I was never under any illusion that it was going to be a tough game. It’s probably good that some guys got to see how they played, because now they know it’s going to be a tough game for us.”
That’s why Clarke – who outlined his priorities for Saturday as “no injuries, performances, results” – was quick to stress that this weekend’s games will be “straightforward”, with the main event being the big draw.
He said there were no “major” injury concerns, with just a few players having “minor complaints”.
“Some players need minutes,” the head coach said. “I have to see one or two players in their position on the pitch and then we have a week to prepare for the first game.
“No effort is being made to protect the players, unfortunately injuries are part and parcel of football. We don’t expect any, but you never know.”