After college, Schwenk played one season for the Chicago Cardinals in the National Football League (NFL), before leaving to serve for three years as a PT boat captain in the United States Navy during World War II.

The 1947 season was his best year as a player, with Schwenk setting a professional football record for passing attempts.

[1] A three-sport athlete, he became a star halfback who both threw forward passes and ran with the ball at Washington University in St.

He set a college football record the following year by running and passing for a combined 516 yards in a single game.

[7] That December, he said he had abandoned plans to play in the National Football League because of World War II.

[6] Limited by an ankle injury, Schwenk played sparingly for the Browns in the 1946 season, substituting on occasion for quarterback Otto Graham.

[7] In November, Schwenk bested his own professional football record, set while with the Cardinals in 1942, of 295 passing attempts in a season.

[7] Schwenk began work in 1950 as the chief operating officer of the Mississippi Valley branch of Junior Achievement, a non-profit that prepares young people for the workforce.