ATLANTA — The U.S. men’s national team had been feeling awfully good about itself heading into this camp after five straight games without a loss and a pair of dominant wins back in November.

What it didn’t have, though — and what it very emphatically still does not have after Saturday — was anything to prove it can compete with the high-level European opposition that makes up most of the world’s best soccer countries.

As much progress as American players have made in getting to Europe and becoming high-impact players there, none is on the level of Jeremy Doku, who utterly dominated them Saturday.

“I felt like the plan was to, obviously, double-team and take him down the line,” said Tim Weah, who drew the primary assignment defending Doku and was too often left isolated out wide. “I felt like we did a pretty good job, but Doku’s Doku — one of the best wingers in the world. He finds his ways to slip past you.”

The Manchester City winger helped set up Belgium’s first three goals in his country’s eventual 5-2 rout of the USMNT. He overran Weah and Mark McKenzie all afternoon in a game that struck some promising notes for the Yanks in the first half before they fell apart early in the second.

The prevailing worries about the back line — the lone spot on the pitch where Mauricio Pochettino’s side is wanting for depth — were certainly not answered as neither McKenzie nor Tim Ream impressed.

McKenzie, who is trying to nail down a spot in the starting XI this summer, was easily beaten by Doku in the buildup to Belgium’s second goal. Alexis Saelemaekers put the ball on a plate for Amadou Onana after Doku had pulled the Americans all out of position.

Tim Ream, who is already likely penciled into a spot in the lineup, committed a handball on Thomas Meunier’s shot after Doku blew by Weah in the buildup, though the Americans were left unhappy with the call. This gave Belgium a penalty that Charles De Ketelaere duly converted to make it 3-1 and put the game out of reach in the 59th minute.

Weah simply had no answer at all for Doku.

While the head coach said this match did not create concerns for the World Cup, it also underscored the importance, for him, of notching games against elite competition before the summer.

“I think we can arrive with the wrong idea of we are so good, we are so handsome, we are so well dressed and we are Americans and good is to feel that,” Pochettino said. “If we want to win the World Cup and we want to go in the group and beat Paraguay [in the June 12 opener], do you think they are not going to fight?”

For good measure, after both teams had made a series of substitutions in a match that allowed up to 11, Dodi Lukebakio scored twice to put the game out of hand. Both goals came on plays where Max Arfsten and Sebastian Berhalter were made to look bad, with the latter prompting boos from U.S. fans as the score reached 5-1.

Playing a 4-2-3-1 base instead of a 3-4-3, with Ream and McKenzie as the center backs, the U.S. shifted to three at the back in possession, with either Johnny Cardoso or Tanner Tessmann dropping between the two central defenders.

Cardoso was taken off after 45 minutes in what was a planned move, though Pochettino praised his play. He did not do the same for Tessmann, noting that both were among the players who failed to help Weah with Doku.

“I think was a little bit lack of understanding,” Pochettino said. “If you see the goal, we have two midfielders, three midfielders that are right to the same line of Tim. They never go to help him. We were talking to help him — always.”

On the positive side, Antonee Robinson was terrific in his first national team cap in almost 18 months, setting up a 1-0 U.S. lead by finding the left foot of Weston McKennie for a volley off a corner.

For McKennie, for Christian Pulisic, for Robinson — three players whose presence on the pitch told you that this was as serious a friendly as the U.S. has played in some time — this was a strong afternoon. Pulisic, though, was left wanting after failing to convert a handful of good opportunities.

“I’m not gonna panic,” said Pulisic, who is suffering a scoring drought at his club, AC Milan. “Better now than in the summer. Things are gonna change and that’s all I can be. Just be positive. That’s it.”