In 1991, Llamosa emigrated to the United States to join the rest of his family, which was at the time living in Queens, New York City.
Llamosa remained with D.C. for the 1999 season, again starting every game he played, including the 1999 MLS Cup, where he helped United to their third championship.
However, at the end of the 2000 season he was traded to the Miami Fusion in exchange for Brian Kamler and a first round draft pick.
After the Fusion folded at the end of 2001, Llamosa was selected 5th overall in the 2002 MLS Allocation Draft by the New England Revolution.
[4] Llamosa was part of the Cosmos coaching staff for the team's return to professional soccer after 28 years dormant.
The Cosmos would cap the season by winning the 2013 NASL Soccer Bowl, defeating the Atlanta Silverbacks 1–0 to take home the title.