He played college football at Santa Clara University, having previously attended Castlemont High School in Oakland, California.

[1] Kenneth Casanega attended Santa Clara University from 1938 to 1942, and played halfback for the Broncos' football team.

Casanega served as a flier aboard an aircraft carrier in the South Pacific,[3] taking part in raids over the Philippines and around Japan.

[3] Casanega joined the original San Francisco 49ers off the All-America Football Conference in 1946.

Upon the death of Cecil Souders on August 31, 2021, Casanega became the oldest living NFL player.