He spent most of his career, both indoors and outdoors, with teams in the western U.S. Pena grew up in Southern California, playing for the Fram-Culver soccer club.
[2] After high school, he chose to forgo college and signed with the Los Angeles Heat of the Western Soccer Alliance (WSA) in 1988.
In 1991, the Blackhawks won the league title, defeating the Albany Capitals as Pena was selected as a first team All Star.
He spent the 1997 season in Los Angeles, but the Galaxy failed to protect him in the 1997 MLS Expansion Draft and the Chicago Fire selected him with their first pick.
However, he expressed his dissatisfaction with this development and on January 27, 1998, the Galaxy traded Chris Armas and Jorge Campos to the Fire for Pena and Kevin Hartman.
While he returned for the 2001 season, the Galaxy sent Pena to the Tampa Bay Mutiny on July 30, 2001, for a conditional pick in the 2002 draft.