He was a right-handed pitcher on the 1977 SIU-Edwardsville team that advanced to the College World Series. The 1977 team was inducted into the SIU-Edwardsville Hall of Fame. Hendrickson also pitched for the SIUE Cougars in 1978 when he was named the Most Valuable Player and All-Conference. His Earned Run Average that year was 2.21. From 1974 to 1976, Hendrickson was a pitcher on the strong Florissant Valley Community College team coached by Larry Adams. During those three years, the Norsemen were a dominant JUCO team in Missouri.

In the early 1970s, Hendrickson pitched for St. Thomas Aquinas High School.

In 1974, he was on the Maryland Heights American Legion team.From 1978 to 1980, he played for the St. Louis Gateways, helping his team advance to the NBC tournament in Wichita all three years. In 1978, the Gateways finished fourth at the NBC tournament. 

In the late 1970s and early 1980s, Hendrickson pitched in the St. Louis County League for Kutis, Giesler-Jorgen, McBride & Sons, and the Sotolar Pointers. He was on several County League championship teams.