Denny was more involved in athletics than football, being a reserve for the Great Britain 4 x 440 yards relay team at the Antwerp Olympics in 1920 and winning eight Yorkshire Running Championships as well as the Lancashire 100yds championship in 1923.
When he joined Southport in December 1921, he had already played for Stockport County and Tranmere Rovers during the 1921-22 season.
None of his 12 games with Southport in the Northern Section yielded him a goal. He also played Rugby League for Castleford.
A fitter by trade, he worked at the Ordnance Factory in the First World War and was involved on the first tank ever made. He later worked for Lyons cakes and turned out for their works team, Cadby Hall. He subsequently worked 25 years for Lever Bros at Port sunlight.