 Happ began the 2008 season with the Phillies' new Triple-A affiliate in Allentown, Pennsylvania, the Lehigh Valley IronPigs.He went 5–6 with a 3.54 ERA in his first seventeen starts, striking out 104 batters in 101⅔ innings.On July 4, Happ was called up to take the place of Brett Myers in the Phillies' starting rotation, after the struggling Myers went to the minors in an effort to regain his form.