Major League Soccer (MLS) is a men's professional soccer league sanctioned by the United States Soccer Federation, which represents the sport's highest level in the United States. The league comprises 29 teams—26 in the United States and 3 in Canada—since the 2023 season. MLS is headquartered in Midtown Manhattan.
The United States Soccer Federation (USSF), commonly referred to as U.S. Soccer, is a 501(c)(3) nonprofit organization and the official governing body of the sport of soccer in the United States. Headquartered in Chicago, the federation is a full member of FIFA and governs American soccer at the international, professional, and amateur levels, including: the men's and women's national teams, Major League Soccer, National Women's Soccer League, youth organizations, beach soccer, futsal, Paralympic, and deaf national teams. U.S. Soccer sanctions referees and soccer tournaments for most soccer leagues in the United States. The U.S. Soccer Federation also administers and operates the U.S. Open Cup and the SheBelieves Cup.
The Lamar Hunt U.S. Open Cup, commonly known as the U.S. Open Cup (USOC), is a knockout cup competition in men's soccer in the United States. It is the country's oldest ongoing national soccer competition. The competition was first held during the 1913–1914 season as the National Challenge Cup, with Brooklyn Field Club winning a trophy donated by Thomas Dewar for the promotion of American soccer. It was renamed and dedicated to North American Soccer League (NASL) and Major League Soccer (MLS) executive Lamar Hunt by the United States Soccer Federation in 1999.
Major professional sports leagues in the United States and Canada traditionally include four leagues: Major League Baseball (MLB), the National Basketball Association (NBA), the National Football League (NFL), and the National Hockey League (NHL). Other prominent leagues include Major League Soccer (MLS) and the Canadian Football League (CFL).
Alan Kelly is a former FIFA Referee from the Republic of Ireland. He has officiated primarily in the Munster Senior League, the League of Ireland and Major League Soccer and was first appointed to the FIFA list in 2002. He has been regarded as Ireland's top referee for the last number of years.
The USL Championship (USLC) is a professional men's soccer league in the United States that began play in 2011. The USL is sanctioned by the United States Soccer Federation (USSF) as a Division II league since 2017, placing it under Major League Soccer in the hierarchy. The USL is headquartered in Tampa, Florida.
Mark William Geiger is an American sports administrator and former soccer referee. He is the senior director of match officials at the Professional Referee Organization (PRO), which oversees domestic referees in Major League Soccer (MLS). Geiger previously officiated in MLS and was on the FIFA International Referees List from 2008 to 2019. At the international level, Geiger refereed the 2012 Olympics, the 2013, 2015, and 2017 CONCACAF Gold Cups, and the 2014 and 2018 FIFA World Cups. At the 2014 World Cup, he became the first referee from the United States to officiate a knockout match at a World Cup tournament. Before becoming a full-time referee, Geiger was a high school mathematics teacher.
Professional Referee Organization (PRO) is the organization responsible for managing the referee and assistant referee program in professional soccer leagues in the United States and Canada, working alongside the United States Soccer Federation, Major League Soccer, the Canadian Soccer Association, the United Soccer League, the National Women's Soccer League, and the U.S. Open Cup.
Allen Chapman is an American soccer referee employed by PRO. He primarily officiates in Major League Soccer.
Andre Jason Blake is a Jamaican professional footballer who plays as a goalkeeper for the Philadelphia Union of Major League Soccer and captains the Jamaica national team.
Drew Fischer is a Canadian soccer referee who regularly officiates Major League Soccer games, and was approved for international matches in 2015.
Professional sports leagues in the United States includes major professional sports leagues, other highest-level professional leagues, and minor leagues.
Brenden Russell Aaronson is an American professional soccer player who plays as an attacking midfielder or winger for EFL Championship club Leeds United and the United States national team.
Joe Fletcher is a Canadian former soccer referee from Niagara Falls, Ontario. He is currently the manager of senior assistant referees for the Professional Referee Organization.
Ismail Elfath is a Moroccan-born American soccer referee for the Professional Referee Organization. He has been a referee in Major League Soccer since 2012 and a FIFA listed referee since 2016.
Charlotte FC is an American professional men's soccer club based in Charlotte, North Carolina. The team competes in Major League Soccer (MLS) as a member of the league's Eastern Conference. The team is owned by David Tepper, who was awarded the expansion franchise on December 17, 2019. It began play in the 2022 MLS season as the league's 28th franchise. Charlotte FC plays at Bank of America Stadium, which it shares with the Carolina Panthers of the National Football League, a team also owned by Tepper; the stadium capacity is reduced to 38,000 for most matches.
Mary Victoria Penso is an American soccer referee. She began her professional refereeing career in the National Women's Soccer League and later moved to Major League Soccer, where in 2020 she became the first woman to referee a regular season match in 20 years. Penso was the referee for the 2023 FIFA Women's World Cup final, the first World Cup final to feature an American referee.
Roman Marcello Celentano is an American professional soccer player who plays as a goalkeeper for Major League Soccer club FC Cincinnati.
Kyle Anthony Hiebert is a Canadian professional soccer player who plays for Major League Soccer club St. Louis City SC and the Canada national team.
Armando Villarreal is an American soccer referee. He has officiated in Major League Soccer since 2012 and was added to the FIFA International Referees List in 2015.
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Esfandiar Baharmast 
Silviu Petrescu 
Alan Kelly 
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