In the 1940 NFL Draft, he was a seventh round draft pick of the Chicago Bears and played four seasons with the Windy City team. During that stretch, he played at both fullback and end, catching 35 passes for 840 yards and scoring 11 touchdowns. His efforts helped the team to NFL titles in both 1940 and 1941, with Pool scoring one of the Bears' nine touchdowns in the 73–0 thrashing of the Washington Redskins in the 1940 title tilt. In 1942, the Bears were undefeated during the regular season, but were upset, 14–6, by those same Redskins in the NFL Championship game.