Diebler played his freshman season at Fostoria High School before his father, Keith, accepted a head coaching position at Upper Sandusky High School, which Jon attended for his remaining three seasons.
Diebler played his freshman season along with his older brother (junior Jake) at Fostoria High School for his father, head coach Keith Diebler. The family left when Keith accepted the head coaching position at Upper Sandusky High School, which Jon attended for his remaining three seasons.