Still a youngster, Martínez was bought by Serie A's Cagliari, arriving from Victoria. He would leave after just one season, having gathered no first team appearances.
In the summer of 2008, Martínez joined Portugal's Rio Ave, although he spent the season with its junior side. Then he left for Peñarol, hoping to gain more first-team experience, but returned home after a few weeks, joining Real España. On August 2012, he signed for Motagua.