However Gelbert also played football at the professional level. From 1898 until 1899, he played for the Duquesne Country and Athletic Club. A year later, he was in the line-up for the 1900 Homestead Library & Athletic Club football team. In 1902, he played for the Philadelphia Phillies of the first National Football League. After the Phillies season ended, he played for the "New York team" during the 1902 World Series of Football The team was heavily favored to win the five team tournament, and featured professional football stars Blondy Wallace, Walter E. Bachman and Ben Roller. However, the team was eliminated in the opening match in a 5-0 loss to the Syracuse Athletic Club.
Finally, Charlie was the father of Charlie Gelbert, an infielder with the St. Louis Cardinals, who would go on to win the 1931 World Series.