Complex sentence: The Cardinals called up Martínez, the number-three prospect in their organization, on May 3,2013, and he made his major league debut against the Milwaukee Brewers at Miller Park that night.
Split into simpler sentences: The Cardinals called up Martínez to the Major League club, the number-three prospect in their organization, on May 3,2013. He made his major league debut against the Milwaukee Brewers at Miller Park that night.