In the Gold Cup final last year, the US lost in a Houston stadium overwhelmingly packed with rival Mexico fans. The semi-final in St Louis, Missouri, was a sea of light blue for their opponents Guatemala.
There were similar scenes at the US-hosted Copa America a year earlier.
It is a huge concern for the US players under extraordinary pressure to deliver as co-hosts at this summer's World Cup, documentary filmmaker Rand Getlin told AFP.
"It devastates them. It hurts them. It makes them sad. They're disappointed in themselves for not giving fans more to cheer for," said Getlin, who spent the past four years embedded with the US team for an HBO series.
"They're like, 'I want to go out, and I want to do something spectacular with this men's national team at the World Cup, so we can change the way the sport is viewed in this country forever,'" he explained.
Getlin's five-part docuseries is appropriately titled "U.S. Against the World."
It takes viewers into the homes and locker rooms of several US stars, including Christian Pulisic and Weston McKennie.
The series charts their journeys from humble backgrounds in a then-soccer skeptical country to unlikely success playing for Europe's top clubs.
It also depicts the sacking of Gregg Berhalter and the arrival of Mauricio Pochettino as head coach less than two years before the World Cup.
Pochettino, the Argentine former coach of Tottenham Hotspur, was quick to note the contrast between the ferocity of the "unbelievable" Guatemala fans and US supporters.
"That is the connection that we would like to see in the World Cup. That connection that makes you fly," said following the Gold Cup clash.
"To see (Guatemala), how they fight, how the fans behave, that is an important thing that we need to learn in this country," he added.
Soccer has boomed in North America over the past decade or so. But the focus of fans' support is often glamorous European clubs or, for immigrant communities, their nation of ancestry.
In recent weeks, outlets including The Athletic have reported below-expectation ticket sales for the United States' World Cup games, though sky-high prices are mainly deemed responsible.
The US will play more Latin American opposition in the group stage opener, against Paraguay, before coming up against Australia and Turkey.
In the documentary, both Pochettino and the players are careful to avoid blaming the US fans for being frequently outnumbered.
For one thing, Getlin said, they are meticulously media trained, especially in "what not to say."
The series shows the vitriol Pulisic received just for opting not to play in the Gold Cup after an exhausting season, in part to prepare for the World Cup.
Pulisic had to delete social media and hurled his phone at the wall in anger at his treatment. In the series, he discusses the mental health toll it took.
"It was brave of him to invite us home at that time," said Getlin, who considers the sometimes prickly Pulisic a "profoundly misunderstood" character.
But there is also a sense among US players that have not yet earned the vast, vociferous home support and loyalty that they witness from other nations.
The US failed to qualify for the 2018 World Cup, did respectably at the 2022 edition, but then suffered embarrassing failures at the Copa America and last year's Nations League.
For every recent loss and poor performance, there is "pressure that's mounting toward the World Cup," admits goalkeeper Matt Turner.
Getlin's hope is that the documentary - which was made in association with the US Soccer Federation - can give American fans an "emotional on-ramp" to get behind their side at the World Cup.
"We wanted to give the United States something to cheer for," said Getlin.
"And in order to cheer for this team, I think you have to know and care about them before the tournament kicks off."