McEwan first played for Eastern Province at the age of 20, and was recommended to Sussex by the future England captain Tony Greig.
But Sussex had its quota of overseas players and in 1974 McEwan went on to the staff at Essex, having played just two seasons in South African cricket and without a first-class century to his name.
[2] With McEwan as its leading batsman, Essex achieved the first successes in its history, winning the County Championship in 1979, 1983 and 1984, the Sunday League in 1981, 1984 and 1985, the Benson & Hedges Cup in 1979 and the NatWest Trophy in 1985.
His career total of 74 centuries is second only to John Langridge's 76 among players who never played Test cricket.
Whilst on Sussex's books, in 1972 McEwan played Worthing Evening Cricket League for Greystoke and in scoring 126* against Lyles, an innings which included seven 6s and thirteen 4s, he secured not only the first century in Division 1 but also the highest league score which still stood as at 1988.