Baker opened the 2008 season as the Twins' fifth starter. He won his first two starts of the season, the first coming on April 4 and the second coming on April 9. However, he placed was on the disabled list (DL) on May 7 with a strained right groin. This was the first DL stint of his career, and it lasted until June 5. On June 15, 2008, Baker became the first Minnesota Twins pitcher to ever throw four strikeouts in the same inning. In the 3rd inning against the Milwaukee Brewers, Baker struck out Ryan Braun, then struck out Prince Fielder, but the ball bounced away from catcher Mike Redmond, so Fielder went to first base. Baker then proceeded to strike out Russell Branyan and Mike Cameron. The last pitcher to record such a feat was Los Angeles Dodgers pitcher Brad Penny, who did it on September 23, 2006 against the Arizona Diamondbacks.