COMMERCE CITY, Colo. — U.S. men’s national team manager Mauricio Pochettino said that AC Milan attacker Christian Pulisic sustained a hamstring injury that forced the player to be substituted in the 28th minute of Tuesday’s 2-1 win over Australia.

Pulisic had already ridden some heavy challenges when he was taken down on a promising counterattack in the 26th minute. At that point, Pochettino made the decision to remove Pulisic from the match.

“[Pulisic] feels something in his hamstring,” Pochettino said. “Tomorrow he will fly to Italy. Tonight we will reassess. We cannot say [anything else].”

Pochettino cited the change of climate between Austin and Denver during this international window as a possible contributing factor to Pulisic’s hamstring issue.

“I think it’s a thing that is a massive risk. I don’t want to say that Christian or if it’s something because, but I think it was really tough for the player,” Pochettino said.

“We know to prepare the game and then to play. We got really sad about this [Pulisic] situation because I think it is difficult. … I think we’re 20 degrees [Celsius] the difference [between Austin and Colorado] and that can affect your body and everything. That is difficult. But yes, that is a thing that we need to fix for the future when we come from Europe because [the altitude] can affect [things].

The U.S. still managed to prevail in Pulisic’s absence, with Pochettino hailing the contributions of Haji Wright and Cristian Roldan.

Wright scored goals on either side of halftime, both assisted by Roldan, including the winner that came on a quickly taken free kick that put Wright in a one-on-one situation with Australia defender Cameron Burgess. Wright evaded Burgess, and then curled his shot around Australia goalkeeper Matthew Ryan. It was a case of Wright seizing his opportunity after Pochettino inserted him into the lineup in place of Folarin Balogun.

“I think that is an important thing, to say, ‘I am here and I want to play. I want to be part of the team,'” Pochettino said. He added, “I think it’s for sure, a player that can perform like today, Haji, can be close to being involved [in the World Cup].”

Wright has been in electric form for both club and country, as he leads the English Championship with eight goals for club side Coventry City. He said the key to his hot start is health.

“The last few seasons of my career I’ve been battling little niggling injuries and it’s been hard to play pain-free, and this is the first season in a few years now where I’m playing completely pain-free,” he said. “So it feels good to be able to … show what I can do.”

Pochettino was even more effusive in his praise for Roldan, who two months ago appeared to be a long shot to make the World Cup squad. Now he’s right in the thick of the World Cup roster chase.

“He’s what we need,” Pochettino said of Roldan.

“We need a player with confidence, with certain belief, with a little bit of romance, with a little bit being competitive. And maybe Christian Roldan is the example of, if you want to build your perfect player, he has a little bit of everything. He’s still not playing in a position that maybe he’s not a striker that should score goals or is not the center back, but he’s a big figure that that balance on and off the field is what we find.”

Australia defender Jason Geria, who was shown a yellow card for a foul against Pulisic, recognized the intense physicality of the friendly match but denied targeting the U.S. star.

“I heard he’s hurt, so I hope he’s OK. We weren’t physical specifically with him. I think in general, we as a team, we as a country, we’re a physical team, and we’re up for a fight regardless of the opponent,” Geria said.

“I wasn’t specifically going out to batter [Pulisic] up or anything. I think all over the park, there were pretty physical battles everywhere.”

The win marked the first time in the Pochettino era that the U.S. prevailed after conceding the opening goal, which in this case occurred when Jordan Bos weaved through the U.S. defense to score in the 19th minute. The comeback came in the wake of another rally last Saturday, when the U.S. battled back to tie Ecuador 1-1.

“It’s no coincidence,” Pochettino said about the comeback.

“The good and the not-so-good, and it’s not a coincidence to have this capacity, to believe, to say, ‘We need to trust in ourselves that is in our mind, in our brain, our heart, it’s in our blood.’

“I think this type of thing is sometimes difficult to explain how that magic happens, but this is about [the] work every day. Every time that we work together is to put the seed and start to be very consistent in our decision in the way that we communicate, and in how the message arrived to the team, to the staff, to everyone.”

ESPN’s Joey Lynch contributed to this report.