Jesse Oster begins his first season with the ThunderBolts in 2011. He was signed on May 5, 2011. Oster has spent most of the last four seasons in the Golden League. He also was signed by the Philadelphia Phillies and played briefly in their system in 2008. In his senior season at Northern Iowa, he went 0-1 with a 6.06 ERA in 16 relief appearances. Jesse attended Foothill High School in Palo Cedro, California.