Mohardt attended the
University of Notre Dame from 1918 to 1921. While there, he participated and received
varsity letters in football, baseball, and track. He was both a pitcher and an outfielder at Notre Dame, compiled a
batting average of almost .330 in three years of baseball, and was the captain of Notre Dame's 1921 baseball team. He also exhibited "an exceptional arm," had speed, and was a good fielder. In football, he played
halfback under coach
Knute Rockne and was a teammate of
George Gipp. Mohardt had "a powerful physique," though weighing only 160 pounds, and with the exception of a broken nose sustained in a football game in 1920, he was never seriously injured in three years of football at Notre Dame. Mohardt was selected as a first-team member of
1921 College Football All-America Team by Lawrence Perry and a second-team All-American by
Walter Camp. The authors of
The Notre Dame Football Encyclopedia wrote of Mohardt: Had he come along at another time or at another school, Mohardt might have gone down as one of the best college football players ever. His misfortune was that he played on some of the best Notre Dame teams in history and in the same backfield as the great George Gipp." In early 1922, Mohardt lost his eligibility to continue playing for Notre Dame after it was discovered that he had played in a professional football game. He was initially alleged with joining other Notre Dame football players in participating in a game for the
Carlinville, Illinois, football team in a professional game, but he denied doing so and claimed he was in class. He was subsequently charged with, and eventually admitted, playing for the
Racine Legion team on December 4, 1921, in a professional game against the
Green Bay Packers. Mohardt also reportedly played semi-pro baseball in Iowa while attending Notre Dame during the summer of 1920, compiling a .309 batting average. While playing in Iowa, Mohardt is reported to have used the alias, John Cavanaugh, which was the name of the Catholic priest who was then the president of Notre Dame. ==Professional baseball==