Career
Sieberts, a forward from Portland, Oregon, went to Oregon Agricultural College (now Oregon State University) where he played basketball and baseball. As a basketball player, he led the Aggies to a Pacific Coast Conference (now known as the Pac-12 Conference) championship and was named first-team all-conference. He was also named an All-American by the Helms Athletic Foundation for his 1915-1916 junior season.
Sieberts quit the Aggies" basketball team during his senior season to enter the business world.
Despite this he was named to the PCC all-conference team for the second consecutive season.