Former U.S. men's national team manager Jurgen Klinsmann said the team's failure to make the 2018 World Cup has set the program back "by several years."
LA Galaxy manager Bruce Arena was installed as Klinsmann's successor, but his second stint in charge of the U.S. ended in disaster.
Arena had the U.S. on the verge of qualifying for Russia 2018 after a massive 4-0 win over Panama in the penultimate match of qualifying, but the U.S. shockingly fell 2-1 at Trinidad & Tobago in its final game to crash out.
Missing out on the World Cup for the first time since 1986 will have dire consequences for the program, according to the former coach.
"It's been set back by several years," Klinsmann told Kicker.
"That was a huge disappointment. The qualification really was never in doubt, but then the lads had a blackout versus Trinidad & Tobago.
"They only needed a point, were too sure of that and underestimated that final match."
Despite the huge setback, Klinsmann is still bullish on the future of soccer in the United States.
"Despite that low point, the football [in the U.S.] is still on the rise," the 53-year-old said.
"Sure, there are a lot of things to catch up on: in the youth academies, in the universities, in joining up the pieces," Klinsmann said.
"But MLS is stable after 20 years. It has role-model character. It has a backbone, mostly thanks to [league co-founder] Phil Anschutz. He kept things together when they could have fallen apart.
"By now, MLS has caught up in the infrastructure. What happened in U.S. soccer in the past 20 years, that is a bit like a fairy tale.
"It still needs patience, but the league's getting stronger with every year."