Guerra arrived in the USA as a refugee in 1982 and attended Bells High School[1] for whom he scored 117 goals in his first three years, which was a record.

[2] As a senior, he played for American Professional Soccer League side Los Angeles Heat until they went out of business in 1990.

Three years later he played for Los Angeles Salsa[3] for whom he scored once in 22 matches in his first season.

[5] Guerra made his debut for El Salvador in an April 1997 friendly match against Guatemala in which he immediately scored a goal, and has earned a total of 13 caps, scoring 3 goals.

[9] His final international game was a March 1999 UNCAF Nations Cup match against Guatemala.