Geer earned all-District 13-3A honors as a freshman and also helped his team to the district championship and to the state tournament two years in a row.

Geer was a two-year starting pitcher for Navarro College where he was voted the conference's most valuable player after posting a 1.78 ERA.

Geer went 4–2 with a 3.96 ERA in 12 games, 11 starts, for Short-Season Eugene Emeralds and the Class-A Fort Wayne Wizards in 2005.

He was promoted to Fort Wayne on August 8 and allowed three runs, two earned, over six innings to win his Wizards' debut the next night.

In 2007, Geer was named the Texas League Pitcher of the Year while pitching for the San Antonio Missions.

He suffered first Big League loss on September 17 against Colorado despite throwing five innings of one-run ball with five strikeouts, as San Diego fell 1–0.

Geer tied for the most starts in one season by a Portland pitcher since the team returned to the PCL in 2001 sharing the record with Junior Herndon in '01 and Dennis Tankersley in 2003.

He missed most of the 2011 season while recovering from stage III melanoma, appearing in just two games for the Triple-A Tucson Padres before undergoing surgery to remove lymph nodes from his neck.