Roach, a left footed flanker, played his early football at SANFL club West Adelaide, for whom he debuted in 1958 and won the SANFL premiership in 1961. He moved to Melbourne in 1964 VFL season and joined Hawthorn but only stayed for two seasons playing 33 games for the Hawks.
In 1966 he returned to West Adelaide and was appointed captain-coach. That same year he represented South Australia at the Hobart Carnival, his second interstate carnival having competed in the 1961 Brisbane Carnival. He was selected into the All-Australian team for his efforts in Brisbane.
After taking a break from the game in 1969 Roach returned to action the following season at his new club Norwood where he would finish his career. When Roach retired in 1972 his final tally of games in the SANFL amounted to 204 and he also represented South Australia on nine occasions. He went on to serve the league as an administrator.
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
