The North American Soccer League is protesting guidelines reportedly proposed by U.S. Soccer that it feels violate antitrust laws.

U.S. Soccer has proposed changes to requirements for a league to qualify for Division I status, according to documents obtained by the Financial Times and New York Daily News.

The NASL said these changes would ensure Major League Soccer is the only Division I league in the United States, hindering NASL's ability to compete.

The proposals for Division I status reportedly include increasing the minimum number of teams from 12 to 16, placing 75 percent of teams in cities of at least two million people, and requiring all stadiums to have capacity for at least 15,000 people.

MLS meets those requirements without a problem, but the 11-team NASL only has two stadiums that would meet the requirement. It plans to add two more teams, in Miami and Puerto Rico, for 2016.

NASL argues that U.S. Soccer is protecting MLS' status as the only Division I league, which it sees as an antitrust violation, and has asked the national federation to revise its multi-tier structure.

New proposals from U.S. Soccer president Sunil Gulati would hinder the NASL's ability to compete, the league says. DON EMMERT/AFP/Getty Images

"Doubling the population criteria now is an anti-competitive bait and switch, with the purpose of entrenching MLS's monopoly position at the very time when the NASL is threatening to become a significant competitor," NASL attorney Jeffrey Kessler wrote in a letter to U.S. Soccer president Sunil Gulati, according to the reports.

MLS' Division I status allows it to place three teams in the CONCACAF Champions League, the winner of which qualifies for the FIFA Club World Cup.

As a Division II league in the eyes of U.S. Soccer, CONCACAF and FIFA, NASL teams can only reach the CCL by winning the U.S. Open Cup. In this year's Cup, only the New York Cosmos beat an MLS team, the expansion New York City FC, before losing ahead of reaching the quarterfinals.

"The financial damage is significant," Kessler told the Financial Times of U.S. Soccer's stance on the matter.

"Simply put, the actions by U.S. Soccer are hindering the league's earnings potential with advertisers, broadcasters and other business partners, who will pay top dollar only for Division I, regardless of the quality of play or passion of the fans."

Neither U.S. Soccer nor MLS responded to NASL's allegations.