Eustice started his career in 1958 with West Adelaide and was a member of their premiership side in 1961. He usually played on the wing at West Adelaide and it was in that position that he won the 1962 Magarey Medal. During his time as captain-coach at Central District he played as a centreman and won their best and fairest award in 1967. He also a best and fairest winner at Glenelg, taking out the award in 1969 as he neared the end of his 224-game SANFL career. A regular for South Australia at interstate football, Eustice was used mostly as a half back flanker.
Victoria (VFL) 16.23 (119) defeated South Australia 7.9 (51), at North Hobart Oval, 11 June 1966, crowd: 23,764 Western Australia 13.11 (89) defeated South Australia 10.14 (74), at North Hobart Oval, 13 June 1966, crowd: 13,969 South Australia 21.20 (146) defeated Victoria (VFA) 9.11 (65), at North Hobart Oval, 16 June 1966, crowd: 10,199 South Australia 14.7 (91) defeated Tasmania 9.13 (67), at North Hobart Oval, 18 June 1966, crowd: 23,368
