World Series of Soccer (MLS)

The term, World Series of Soccer, was originally used for a series of senior international soccer matches hosted by the United States Soccer Federation between 1991 and 1994. In 2005, Major League Soccer re-introduced the name for a series of professional matches in the United States

In 2005, Major League Soccer (MLS) began the World Series of Soccer (WSS), a series of games pitting MLS and big name international clubs against each other. The games took place across the United States. The WSS was a round robin style competition between two MLS teams: D.C. United and Chicago Fire as well as two European powerhouses: Chelsea of the English Premiership and Milan of Italy's Serie A. The games were played during the MLS season, the European off-season.

In 2006, MLS continued the WSS and expanded it to include Real Madrid and Barcelona from Spain, Celtic from Scotland, Everton from England and Club América, Necaxa and Tigres from Mexico.

The World Series of Soccer returned in 2007 as a four-team affair, primarily used to promote the arrival of English footballer David Beckham to the United States. His Los Angeles Galaxy had a round-robin with Chelsea of the Premier League, the Suwon Samsung Bluewings of the K League, and the UANL Tigres of the Primera División de México. UANL Tigres won the competition by virtue of goal difference over Chelsea.