A third-round pick of the Astros in 2001, the Cal State Fullerton product debuted with Houston the following year, making 17 starts and notching a 6-7 record but with a 6.01 ERA. In 2003, he pitched more from the bullpen and went 2-1 with a 4.93 ERA in 36 games.

Traded early in the 2004 season to Oakland for Chad Harville, Saarloos has both started and relieved during four seasons with the Athletics and one with the Reds. In 2009, he was signed by the Indians but did not reach the majors. For his career, he has a 29-30 record with a 5.02 ERA and two shutouts.