Recruited from Barwon in the Geelong & District Football Association, Hagger played as a key position forward and was known for his high marking and ability to kick goals from difficult angles.
Named captain-coach of Geelong in 1924, Hagger was captain for only one season, handing the job over to Cliff Rankin.
In 1925 Geelong won the premiership and Hagger was the League's leading goalkicker, with 78 for the season.
Late in the match Hagger was momentarily knocked out but recovered in time to refuse to leave the ground after a stretcher had been called.
Victoria 15.13 (103) defeated Western Australia 14.11 (95), at North Hobart Oval, 9 August 1924, crowd: 15,687 Victoria 14.26 (110) defeated New South Wales 4.6 (30), at North Hobart Oval, 12 August 1924, crowd: 350