|Full name||Gerson Levi Mayen Villavicencio|
|Date of birth||February 9, 1989|
|Place of birth||Los Angeles, California, United States|
|Height||5 ft 8 in (1.73 m)|
|2010||→ Miami FC (loan)||9||(0)|
|2011||→ Fort Lauderdale Strikers (loan)||11||(1)|
|2012||Los Angeles Misioneros||6||(0)|
|2008–2009||United States U20||6||(0)|
* Senior club appearances and goals counted for the domestic league only and correct as of 2016.
Mayen attended Manual Arts High School, and started playing soccer when he was young with a club named Gilbert Lindsay Youth Soccer Club, then with the club soccer with Alta Loma Arsenal where he won four Cal South State Cups, four Regional Championships and three National Championships. Mayen also won two Golden Boot awards. Rather than opting to play collegiate soccer, Mayen joined the Chivas USA U-18 team.
Mayen was signed to a full professional contract by Chivas USA on March 27, 2008 after training with the club throughout preseason. He did not make an appearance with the first team in his rookie season, but made 12 appearances in the MLS Reserve Division, playing primarily as a defender and defensive midfielder. He made his professional debut on 29 March 2009, in Chivas's game against FC Dallas.
On August 6, 2010, Chivas USA sent Mayen, along with teammate Chukwudi Chijindu, on loan to USSF Division 2 Professional League side Miami FC. Mayen returned to Florida in July 2011 when he was loaned to NASL club Fort Lauderdale Strikers.
Mayen was traded with Justin Braun to MLS expansion side Montreal Impact for James Riley and allocation money on November 23, 2011. However, Mayen was waived by Montreal on March 1, 2012 prior to the start of the 2012 season.
Mayen has made one appearance for the United States U-20 men's national soccer team, in the Campos Verdes International Tournament in Portugal in 2008. Mayen was also named to the 2009 Under 20 World Cup in Egypt where he started and played 90 minutes against Germany.
On July 5, 2011, Mayen was given permission by the FIFA to be part of the El Salvador team. "After a thorough review of the documentation submitted by the Salvadoran Football Federation, the judge concluded that the player Gerson Mayen Villavicencio meets the objective conditions stipulated in Article 18, paragraph 1 of the Regulations Applicable Statutory of the FIFA: in particular, the player Gerson Mayen has never played an international "A" match in an official competition representing the U.S. Soccer Federation," reads the resolution of FIFA. Mayen made his international début at the 2013 Copa Centroamericana, coming on as substitute at the minute in El Salvador 1–1 draw with Honduras.
|2008||Chivas USA||United States||Major League Soccer||0||0|
|Miami FC (loan)||USSF D2 Pro League||9||0|
|2011||Chivas USA||Major League Soccer||4||0|
|Fort Lauderdale Strikers (loan)||North American Soccer League||8||1|
|2012||Los Angeles Misioneros||USL Premier Development League||6||0|
|2012-2014||CD FAS||El Salvador||Salvadoran Primera División||10||1|
- "Gerson Mayén recibió aval de FIFA" [Gerson Mayen was endorsed by FIFA] (in Spanish). July 5, 2011. Retrieved July 5, 2011.