LOS ANGELES -- In the wake of the U.S. men's national team's 1-0 defeat to Panama in the semifinals of the Concacaf Nations League (CNL), it's fair to say it's time for USMNT fans to worry about the 2026 FIFA World Cup.

The U.S. has shown flashes of stellar play since manager Mauricio Pochettino took over last September, especially in the CNL quarterfinal series with Jamaica. But Thursday's semifinal exit exposed some old troubles.

The USMNT's lack of aggression to start matches, especially when the opposition cedes possession, remains a problem. That leads to an inability to break down tightly packed defenses. And though Panama has emerged in Concacaf as a tough-to-break-down unit, if the Americans can't consistently get past the Canaleros, who have beaten the U.S. three straight times in tournament play, how can the USMNT expect to get out of a group at the World Cup?

That isn't to say that all hope is lost for the Americans -- far from it. But with just 447 days between now and the start of the World Cup, Pochettino has little time and few opportunities to turn things around.

This summer's Concacaf Gold Cup -- the USMNT's only competitive games before the World Cup -- has taken on increasing importance. It will allow Pochettino an extended camp to further familiarize himself with his players. The U.S. will also host friendlies against Turkey and Switzerland before Gold Cup matches to mimic the cadence of the World Cup.

The hope -- which is not guaranteed based on Thursday's performance -- is that the players will get more experience in knockout games. But on this front, Pochettino's plans are being undermined by the Club World Cup, with the Juventus duo of Weston McKennie and Timothy Weah, along with Borussia Dortmund's Gio Reyna, all possibly unavailable for the Gold Cup due to their respective clubs' participation.

After that, and with no CNL scheduled for 2026, there are just four more international windows in September, October, November of 2025 and March of 2026, plus some pre-World Cup friendlies. That is a scant amount of time to further refine things.

And there is plenty this U.S. team needs to refine, especially with the ball.

To get a sense of how toothless the American attack was against Panama: The U.S. had 811 touches, the 11th time the Americans have had more than 800 touches in a game since September 2017. But they had an expected goals, or xG, of 0.68, making it the first time in that span that the U.S. had over 800 touches but an xG below 1.00. That shows the U.S. had plenty of time with the ball, but struggled to create dangerous scoring chances.

The return of several injured players would greatly help the U.S. cause. The U.S. has badly missed right-back Sergiño Dest, who has recently returned for PSV Eindhoven after suffering an ACL tear 11 months ago. Dest is the ultimate attacking wild card who can deliver the unexpected, either off the dribble or striking at goal. Left-back Antonee Robinson and his marauding runs down the flank were also missed against Panama.

The two absences have a massive effect on the way the U.S. plays. Joe Scally is a capable, defense-first option, but isn't one to contribute much to the attack. That's why in Dest's absence, Scally usually stays home and allows the opposite full-back to get forward. But Yunus Musah seems miscast as a wing-back, given his distribution limitations.

The frontline has also been beset by injuries, with Folarin Balogun and Ricardo Pepi out for long stretches. Their returns would increase the competition for places in attack that have lacked a certain spark.

All these absences lead to questions about the depth of the USMNT's player pool. But in situations like Thursday's loss to Panama, the U.S. would also be aided by Pochettino tilting the lineup more toward attack. Against a team bunkering in, Tanner Tessmann's presence in the midfield seemed redundant given that the defensively dependable Tyler Adams was back in the team. That would've freed a spot for a more creative player such as Reyna or Diego Luna in the middle.

Yet the team's mindset might be Pochettino's most difficult challenge. The U.S. manager pointed to a "lack of aggression" in the first half, which he described as "painful" to watch.

This was illustrated by the Americans' touches in Panama's box. The U.S. had 32 touches in the Panamanian penalty area. That ranks 12th in the USMNT's past 35 games. But only nine of those touches came in the first half. When Tim Weah started occupying wider positions in the second half, the U.S. made more headway.

Pochettino needs to create competitive tension for playing time. But are the players who could take on bigger roles good enough to unseat any incumbents? Solving the aggression puzzle won't be easy. Some players are proving not as capable as their club reputations dictated at one point.

Pochettino has attempted to bring in reinforcements, mostly from MLS clubs, and has talked up how they'll get chances to impress. But until he gives those players more prominent roles, his words will feel empty.

Still, there are limits to how much Pochettino can do as a manager. At some point, the onus is on the players to improve, and channel the aggression required.

"You always learn more from setbacks than you do from games that, say, we would've won, that you're papering over the issues that I think everybody saw in terms of getting behind and aggression and all that," U.S. defender Tim Ream said. "There's always teaching moments, there's always learning moments in every game, every training, every day that you step on the field and we have to look at that and make sure that we take on board exactly what he wants, take on board exactly what he needs and that starts with the duels and the aggression and the intensity."

The USMNT will miss a chance to defend their CNL title after winning the past three, but Sunday's third-place game against a very motivated Canada will be an opportunity to put those lessons into practice.

With Alphonso Davies, Jonathan David and Cyle Larin available, it seems likely Canada will be more adventurous than Panama in attack. But Pochettino shouldn't change his entire starting 11. He should continue to establish chemistry. Playing time needs to be earned, as well. But there seems to be some opportunities for players.

Zack Steffen appears to be a clear choice in goal, given Matt Turner's suspect positioning on Cecilio Waterman's game winner, when he was shaded too close to his near post. Reyna or Luna in taking Tessmann's place seems another obvious swap. Patrick Agyemang looked active in his 22 minutes against Panama.

At minimum, USMNT fans will want progress. That bar is low after the poor showing against Panama. But with just under 15 months left to the World Cup, the U.S. needs to show signs that it's moving forward again.