He played mainly as a wingman or as a half forward flanker; however, he finished his career as a back pocket player.
[1] He played in the Thirds (under-19s) and the Seconds (Reserves) until he played his first senior match for Essendon on 19 July 1952, round 13 of the home-and-away season, against Footscray, at Essendon's home ground, Windy Hill.
All but one, A. Taylor, of the premiership team's 20 players had either already played for the Essendon Firsts or would go on to do so in the future.
Whilst the Essendon senior side, again with Sewell as assistant coach, lost the 1968 Grand Final — Essendon 8.5 (53) to Carlton 7.14 (56) — Sewell finished his coaching career with a triumph.
Sewell's family have been involved in the foundry business for three generations and Greg was for many years in control of Greg Sewell Forgings Pty Ltd.[3] He was a good mate of John Coleman and was the last person at Essendon to see John Coleman alive.