McEwan scored consistently for Canterbury for over a decade. His best seasons were 1983–84, when he scored 713 runs at 59.41, and 1989–90, when, aged 36, he scored 758 runs at 44.58. In his last season, 1990–91, he scored over 500 runs at 43.41. One of the best examples of his attacking batting was when his 155 and 35-ball 50 against Auckland won the Shell Trophy for Canterbury in the last game of the 1983–84 season. In 1984–85 McEwan was brought in as a late replacement for the Young New Zealand tour of Zimbabwe under the captaincy of Jeff Crowe. He was the New Zealand team's highest scorer, with 364 runs at 91.00 in the four games, after a first-ball duck in the first.