Australia coach Tony Gustavsson (49) said Kerr's availability is "down to the wire" for their final Group B match at the Women's World Cup, after the Chelsea forward, the Matildas' leading goalscorer, sat out two matches with a calf injury.
Canada can oust the host nation with a win or draw at Melbourne Rectangular Stadium.
"Obviously, the team has to be prepared to play a world-class player like Sam Kerr, and we'll be ready for that. But ultimately, we've got to get us right," Priestman told reporters on Sunday. "So ultimately, does it affect me? No. How much have we spoke about if she is or if she isn't? We haven't.
"We spoke about what it's going to take to beat Australia because Australia aren't just Sam Kerr."
Priestman said Sinclair, who limped off the field after Canada's 2-1 win over Ireland, and Kadeisha Buchanan (27), who was battling an illness, will both play.
"Yes, they both trained today," the coach said.
Sinclair, who is playing in her sixth World Cup, trained with kinesiology tape around her right knee and warmed up with a resistance band under the watchful eye of a trainer, but appeared to be running well.
Priestman's reigning Olympic champions are hoping for their first World Cup medal, with a best-ever finish of fourth in 2003. Australia's best finish is sixth (2007), but they have not missed the knockout round since 2003.
Asked what her team will need to beat the Aussies, Priestman said, "We have to bring us.
"There's a lot around what might come up in front of us, but ultimately, I know that this team, if we turn up - and we turned up in the second half (against Ireland) for sure - that we'll go and get three points. The focus is to be brave and bring what we bring and bring it well."
Canada's Olympic gold came in an empty Tokyo stadium due to COVID-19, while Monday they play in what will surely be a sea of Australian green and gold in a do-or-die game for their opponents.
Who will be shouldering the most pressure?
"Pressure is what you make it," Priestman said. "Do I think the game (Monday) is purely won on Xs and Os? Possibly not. It's actually who can cope with the occasion and bring out the experience, and I think we've got that in abundance."
Nigeria and Canada, who played to a scoreless draw in their opener, top Group B with four points, while the Matildas have three. Nigeria play winless Ireland on Monday.
Asked by an Australian journalist if she is keen to knock the host nation out of the World Cup, Priestman laughed and answered diplomatically: "Three points. That's all I'm focussed on, is to get three points and move on."
"I'm not going to make a headline around knocking the home nation out of the World Cup. Ultimately we want to win so if that means that we knock out Australia, we knock out Australia."
