He played football for Eton and Exeter College, before becoming a member of the Oxford University team, for whom he played as a forward, famed for his "speedy runs". Despite having graduated several years earlier, and being an ordained clergyman, Johnson was selected as a member of the University team that played in the 1874 FA Cup Final, although all the other ten members of the side were undergraduates. Of the eleven members of the university team, four (including Johnson) became clergyman and five took up the law as a profession. In the final, played at Kennington Oval on 14 March 1874 against a team from the Royal Engineers, the university ran out as 2–0 winners, with goals from Charles Mackarness and Frederick Patton.