Klein, born and raised in the Pacific Palisades in California, was an athletic standout at Corpus Christie Elementary School, then St. Monica High School. After High school, Klein attended the University of Southern California, where he was the starting tight end for the Trojans' 1967 national championship team. Following his senior season, he was drafted 21st overall in the 1969 NFL draft by his hometown Los Angeles Rams where he played from 1969-1976. Klein finished his pro career at the San Diego Chargers from 1977–1979.
When Klein is not busy with his incredible family legacy, he serves as the President and CEO of the Saint John’s Health Center Foundation and oversees the management of all philanthropic development efforts.