Detroit exercised a $6 million option to keep him for 2013 .
Peralta , 31 , made his second All - Star team this year and is set to become a free agent at the end of the season .
Detroit exercised a $6 million option to keep Peralta for 2013 .
Peralta , 31 , made his second All - Star team this year and is set to become a free agent at the end of the season .