Igawa saw a decline in performance in 2004 and . In 2004, despite leading the league at 228 strikeouts, he went 14-11 with a 3.73 ERA. In 2005, Igawa went 13-9 with a 3.86 ERA, fifth among his team's starters in ERA, and was briefly exiled to the minors. He was only tied for fifth in strikeouts (down significantly to 145) and 10th in ERA, but was still third in the circuit in victories. While still a productive hurler, Igawa became a target of enthusiastic fan criticism due to his inability to perform at his prior level.