loewen grew up in surrey, british columbia, and was both a starting pitcher and first baseman for kennedy-surrey little league, the team that represented canada at the 1996 little league world series in williamsport, pennsylvania. he would go on to attend fraser valley christian high school and play baseball for the whalley chiefs of the british columbia premier baseball league. he committed to play college baseball at arizona state. while still in high school, he pitched a no hitter against the dominican summer league pirates for the canadian national baseball team.