A native of Cartago, Fonseca played the majority of his career at local side Cartaginés.

[4] Fonseca played at the 1999 FIFA World Youth Championship held in Nigeria.

[5] He made his senior debut for Costa Rica in a February 2003 UNCAF Nations Cup match against Honduras and collected a total of 28 caps, scoring 2 goals.

[5] He was the first player to be booked in the FIFA World Cup 2006 during his country's 4–2 defeat to Germany.

This biographical article related to Costa Rican association football is a stub.