Clayton Mortensen is 2-4 with a 7.12 ERA in seven big league starts. (Mark Duncan/AP)

The A's and Rockies exchanged pitching prospects on Monday, when Oakland sent Clayton Mortensen to Colorado in exchange for Ethan Hollingsworth.

Mortenson, a former supplemental-round draftee, has pitched in the Major Leagues in each of the last two seasons, whereas Hollingsworth, a former fourth-round draftee, has pitched just two games above Class A.

Mortensen, the 36th overall selection in the 2007 First-Year Player Draft, began his career with the Cardinals before being sent to Oakland as part of the trade that netted St. Louis Matt Holliday in 2009. The right-hander made 26 starts for Triple-A Sacramento last season, notching a 13-6 record and a 4.25 ERA and striking out a career-high 112 batters.

Mortensen has posted a 31-27 record with a 4.29 ERA during his four-year Minor League apprenticeship, and he's gone 2-4 with a 7.12 ERA in seven big league starts. The 25-year-old made just one start for Oakland last season.

Colorado was forced to designate right-hander Samuel Deduno for assignment in order to make room for Mortensen on the 40-man roster.

Hollingsworth, just 23 years old, was selected by the Rockies in the 2008 First-Year Player Draft. The right-hander notched a 12-8 record and 3.31 ERA for Class A Modesto, striking out 153 against just 34 walks. He made a brief debut at Double-A Tulsa late last season, and for his career, he boasts a 24-24 record and 4.33 ERA.