After the United States men failed to qualify for the Olympic Games on Sunday, former Mexico national team assistant coach Mario Carrillo said he felt the U.S. made a mistake to not include the core of promising players under the age of 23, including Christian Pulisic, Tyler Adams, Weston McKennie and Sergino Dest.

Those players, all with European clubs, were not available to play in Guadalajara because their clubs were not obliged to release them for Olympic qualifying. U.S. Soccer opted instead to suit them up for senior team friendlies.

But Carrillo said by doing so, the U.S. loses a key step in player and national team development.

"I think they were very arrogant," said Carrillo on Sunday's edition of Futbol Picante on ESPN Deportes. "You should never miss out on the Olympics. The level of play at a tournament like that is very important [to prepare] for the World Cup."

The United States lost 2-1 to Honduras in the CONCACAF Olympic qualifying semifinals on Sunday, missing out on the Olympics for a third consecutive time.

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After beginning the tournament with two straight wins over Costa Rica and the Dominican Republic, the Americans lost to Mexico in the Group A finale, and then to Honduras.

Both Mexico and Honduras will qualify for Tokyo and face off on Tuesday for the championship.

The Olympic skid for the U.S team is part of a trend that includes the senior national team missing the 2018 World Cup.

Since hosting the 1996 Games in Atlanta, the American men have only made it back to the Olympics twice and last did it in 2008.

Carrillo served as the assistant coach to Manuel Lapuente at the 1998 World Cup, and then to Javier Aguirre at the 2010 finals in South Africa.

In Liga MX, Carrillo managed Club America to its Clausura 2005 title and the Mexican Campeon de Campeones trophy.

The former Cruz Azul and Pumas boss highlighted the importance of the player development process that led up to El Tri's gold medal at the London games.

"[Some of] the current starters for the Mexican team are the same who won at the Olympics back in 2012," Carrillo stated.

Of the group who beat Neymar and Brazil in the London final, only Raul Jimenez of Wolverhampton Wanderers and Hector Herrera of Atletico Madrid are mainstays for Mexico manager Gerardo Martino during the run-up to the next World Cup.

However, Carrillo reiterated the value of having the United States play in high-level international matches at any age level, especially if the United States figures to qualify out of CONCACAF for the 2022 World Cup in Qatar.

"The United States should have qualified for the Olympics," Carrillo said. "They should have hired a great coach to take them there because those games would have very important before the World Cup."

Both the U.S. and Mexico squads at the tournament in Guadalajara featured dual nationals who are ultimately eligible to represent the other nation. Mexico's Santiago Munoz was born in El Paso, Texas, while David Ochoa, Julian Araujo, Sebastian Saucedo and Sebastian Soto from the United States are all eligible for El Tri through their parentage.

Those players, like Efrain Alvarez, who is currently training with the Mexico senior team, are all still eligible to file a one-time switch back to either the United States or Mexico in accordance with FIFA's statutes.

After the qualifiers and the Olympics were postponed for one year due to the pandemic, FIFA maintained the requirement that players be born Jan. 1, 1997, or later. Olympic men's soccer has been an U23 tournament since 1992.

U.S. Soccer will be represented by its world champion women's team in Tokyo. They will be a favorite to claim a fifth gold medal. The U.S. men have have participated in the Olympics four times but have never won a medal.

"We lose an opportunity to play in an international tournament with more pressure, where these players have to be in these environments and continue to improve with that pressure,'' U.S. coach Jason Kreis said.