 Consequently, Shannon signed a one-year contract to play professionally with the Providence Steamrollers of the BAA.He averaged 13.4 points per game in 1948–49 and was named the league's Rookie of the Year, a designation not currently recognized by the NBA for that season.Although he had already signed and played with Providence, the team was still required to select him in the 1949 BAA draft to secure his rights.