And the US coach says his charges must match Australia's "mindset" to get a crucial three points that could determine who tops Group D.
Pulisic hasn't trained with his teammates all week, including on Thursday, as he deals with a left calf issue.
The 27-year-old dubbed 'Captain America' picked up a calf knock in training last week and was withdrawn at halftime of the US's 4-1 win over Paraguay after starring in the first half.
Pochettino said he would meet with medical staff on Thursday before making a decision on whether Pulisic features on Friday (5am Saturday AEST) at Seattle Stadium.
"He's evolving, he's much better from Friday," Pochettino said.Â
"We'll see ... if he is not available for tomorrow, he will be available for the next game, and I think he's doing a massive effort trying to be ready.
".... When this type of thing happens, it always is painful, but I think Christian is strong and with a great mentality, and is doing a fantastic effort to try to be ready as soon as possible."
Popovic said the Socceroos were prepared whether Pulisic played or not, while Pochettino was non-committal on who could potentially replace him.
Gio Reyna, Brenden Aaronson, Tim Weah and Alejandro Zendejas appear among the potential options to try and unlock Australia's defence.
Pochettino hailed Australia's defence and their well-executed long passes to their attacking "arrows" - presumably Nestory Irankunda and Mohamed Toure.
The US coach said last year's feisty 2-1 win over Australia in Denver, which he likened to more of a "street game" than a friendly, had been a wake-up call and one of the most difficult games they had played.
Pochettino insisted his team was "ready to fight" against Australia and needed to be "on the edge of the line".
"We need to believe in the same way that they believe if we want to compete, because they compete really, really well," Pochettino said.
"They are very aggressive, they have a great organisation.
"You can see that it was difficult for Turkey to create chances, clear chances. And then, in the moment that they recover the ball, they have arrows in front, and they transit so quick, so fast."
"But for me it's the mentality, the coach's mentality - Popovic. I was talking with him in Denver and I really appreciate him and really like him.
"The mentality of the whole team, they create a great mentality. And it's difficult to play against a team that really believes in what they are doing."
