Comerica Park in Detroit isn’t a hitters’ park, but it’s a good place for Pena to go relax and be himself. He had disappointed some in Oakland who thought he was more advanced than he showed to be, and reliever Franklyn German (who also went to Detroit in the deal) is another tools guy Beane always uses — like Jesus Colome, Jose Ortiz and Mario Encarnacion — in deals such as this.