 In 2009, during the 2009 AL Central tie-breaker game featuring the Twins against the Detroit Tigers, Casilla became the unlikely hero, hitting a game-winning walk-off single to score Carlos Gómez from second base in the bottom of the 12th inning.Prior to the season, Casilla changed his number from 25 to 12, giving number 25 to Jim Thome, who had worn the number for almost his entire 21-year career.For most of the season, Casilla switched between second base and shortstop, sometimes filling in for Tsuyoshi Nishioka, who was injured for the first two months of the season.