USA threatened to pull off an upset at Mercedes-Benz Stadium, as Weston McKennie put it ahead in the 39th minute.

However, goals from Zeno Debast, Amadou Onana and Charles De Ketelaere saw Belgium storm into a 3-1 lead, before substitute Dodi Lukebakio added two more.

Patrick Agyemang pulled a goal back for US late on, but the defeat was its heaviest in a home game where it had opened the scoring since May 1959, when it lost 8-1 to England.

But after ending 2025 on a five-match unbeaten streak (four wins, one draw), Pochettino feels a reality check could be a good thing for his team, who open their Group D campaign against Paraguay in Los Angeles on June 12.

"To feel pain is sometimes good," Pochettino said. "It is true that we lost 5-2 and from there, you can't say anything that can convince people there are positives.

"But I think there are many positive things that we are seeing in the dressing room, and these types of results, it is better if they happen now.

"It's a good reality check for us. I think we need competitive games to arrive at the World Cup at our best. 

"We cannot arrive with the wrong idea that we are so good, thinking, 'we are so handsome, we are so well-dressed and we are Americans.'

"It's good to feel that, but if we want to win the World Cup, if we want to go to the next round and we want to beat Paraguay, do you think that they are not going to fight?"

Christian Pulisic failed to hit the target with any of his three shots, and he has now gone seven games without a goal for the USA, last netting on the international stage in November 2024.

"We have to beat teams like this if we want to have a chance to go far in the tournament," Pulisic said.

"Of course, I'm disappointed. I have to finish my chances. They were not easy chances, but there were certain moments where I expected to do better, for sure."

Things do not get any easier for Pochettino's team, either, as it face Portugal in another high-profile friendly on Wednesday.