After graduating from high school, Alfson worked and farmed for several years until earning enough money to attend the University of Nebraska-Lincoln, Class of 1941, where he was a member of the Chi Phi Fraternity. When he attended school, he decided to try out for the Cornhusker football team, but as a lineman. After one year on the freshman squad, he asked the school's permission to continue practicing, but to not play, so that he could get himself into proper condition as well as to wait for the upperclassmen ahead of him to graduate. This made Alfson the first recordedredshirt in Cornhusker history, and likely the first in collegiate history - the inventor of "redshirting" - the Nebraska color without a number. Alfson's year of conditioning would pay off well, as he returned to become a three-year starter for Nebraska. In the era of one-platoon football, he was a guard on offense, and a linebacker on defense, and he wore jersey number #22 throughout his Cornhusker career. He would ultimately become recognized as first team All Big Six Conference in 1939 and 1940, second teamAll-America in 1939, and he would earn first team All-America status in 1940, the year the Nebraska Cornhuskers went 8-2 and played Stanford in the 1941 Rose Bowl under coach Biff Jones.
NFL career
Alfson would play one year with the NFL's Brooklyn Dodgers, and earned NFL All-Rookie status, despite being drafted in the sixteenth round due to his age. However, World War II cut his career short, and Alfson married and served in the war.
Post-war
After the war he returned to Wisner and farmed, and he also served on the Wisner school board as well as other organizations, and also briefly served as Wisner's mayor. He also took great pride in his Cornhusker connections, and attended many Nebraska games. In 1975, he was inducted into the Nebraska Football Hall of Fame. In 2005, Alfson was recognized with 'honorable mention' recognition for the state of Nebraska's "Our Top 100" athletes of all time, as selected by the Omaha World-Herald. Alfson died in his home in Wisner, Nebraska, in 2001. He had two daughters and one granddaughter.