 In , Thornton was briefly sent back down to high-A ball with the Inland Empire 66ers of the California League, but was quickly promoted back up AA ball with the San Antonio Missions again.He started only 4 games, but posted an incredible 0.36 ERA, with a 3–1 record, gave up only 8 hits in 25.1 innings of work and struck out 18 batters.His performance got him promoted that same year to AAA ball with the Tacoma Rainiers in the Pacific Coast League.