A 30-year old out of Santo Domingo, Dominican Republic, Martinez pitched for the Brewers in 2003. In four starts he was 0-3 with a 9.92 ERA. In 16.1 innings he struck out 10 while allowing 25 hits and 15 walks. He has been playing professionally since 1998 and last pitched for Saltillo in the Mexican League (AAA) in 2008. His best season was 2003, when, in addition to his Major League call-up, he went 4-0 with a 0.99 ERA in seven starts for AAA Indianapolis. He struck out 46 in 45.2 innings.