Ken started his baseball career at an early age with Eugene Little League. Although he gained awards in all three sports, football, basketball, and base­ball, it became evident as the years passed that baseball was to be the sport he would excel in. After moving to Medford, he attended Hedrick Junior High where he played basketball and football. Upon entering high school, he participated in basketball and baseball, playing on State Champion basketball and State Champion baseball teams.

He was chosen All-State Catcher and claims the highlight of his career came when, with four-year teammates, Jerry Anderson (pitcher), Lowell Dean (1st- baseman), and Calvin Dean (outfielder),  played together in the State All-star game. Medford coach, John Kovenz said of Ken, “I’ve never seen a better catcher in high school than Ken Jensen.”

Ken attended the University of Oregon on a 4-year baseball scholarship. As a baseball standout for the Ducks, he was co-captain with Sandy Nosier of the Northern Division Champion baseball team.

Ken signed a bonus contract with the Kansas City Athletics and later played in a minor league system.