Steuber was drafted by the NFL's Chicago Bears and played one game for the team, appearing as a substitute on September 26, 1943, in the Green Bay Packers' home opener, which ended in a 21–21 tie.

He was limited by a knee injury that year, however, and was traded to the Los Angeles Dons after the Browns won the first AAFC championship game.

[6][7] He was third in the country in rushing that year with 855 yards as he and fellow halfback Harry Ice led a Missouri ground attack that ranked first in the nation.

[4] Missouri won the Big Six Conference championship and faced Fordham University in the Sugar Bowl at the end of the season.

[15] Steuber was selected in the first round of the NFL draft by the Chicago Bears, but he played in only one game for the team during the 1943 season before departing for the U.S. Navy during World War II.

[16][17] As the Bears went on to win the NFL championship, Steuber entered the Navy's pre-flight training college and was transferred to DePauw University in Greencastle, Indiana, where he played basketball and football for the school's teams.

A controversy arose after an official at the Amateur Athletic Union objected to Steuber's participation in a meet because he had played professionally for the Bears.

[21] At the end of the year, he moved to the Ottumwa Naval Air Station in Iowa and played for its Skyers football team.

[24] Steuber saw limited action with the Browns due to a knee injury, but the team posted a 12–2 regular-season record and won the first AAFC championship game.