Jeff Harkensee enters his first year as a ThunderBolt and second as a professional in 2013. He signed with the team on January 7, 2013. Harkensee began his professional career with the Sonoran Explorers of the Freedom League in 2012, finishing ninth in the league with his .336 batting average. Prior to that, he spent two seasons at Southeastern Louisiana University where he hit .317 with 16 home runs and 102 RBIs in 116 games. Jeff attended Buffalo Grove High School in Illinois.