At the suggestion of the owner of his semiprofessional team, Martínez attended a tryout held by the Seattle Mariners of Major League Baseball (MLB). Despite nearly missing the tryout after a long night working at the factory and being "so tired couldn't swing the bat," The Mariners signed him to a contract with a $4,000 signing bonus (a small amount at the time) on December 12, 1982. He initially considered declining the offer, due to the money he was making in Puerto Rico, but Carmelo convinced him to sign.