State representative honours first came his way in 1984 when he was called into the New South Wales Blues side for all three games of that year's State of Origin series. Thereafter barring injury (which ruled him out of the 1987 series) and his surprise omission in 1989 (which saw NSW suffer their second straight 3-0 defeat by Queensland), he was generally a regular Blues starter and he made 17 State of Origin appearances until Game 2 of the 1991 series. When Jack Gibson was New South Wales coach in 1989 and 1990, he reportedly threatened the NSWRL with resignation from the position if Roach was selected in the side, though the Balmain front rower was selected in 1990 and went on to win their first series since their 3-0 win in 1986.