A first round pick in the 2007 Amateur Draft, Clayton Mortensen made his Major League debut on June 29th of t2009. A former hurler from Gonzaga, Mortensen was 7-4 with a 4.24 ERA in 14 starts with Triple A Memphis before his call up.
On July 24th, Clayton was traded to the Oakland A's in the deal that saw Matt Holliday go to St. Louis.