Originally from Lyndhurst, Hampshire, McCarthy played the majority of his professional career with Football League club Southampton, before finishing his short career with brief spells at Poole Town, Cowes Sports, and Andover.
Originally from the New Forest area, McCarthy grew up a fan of Southampton and is said to have wanted to join the club since he was a youngster.
[1] After playing his youth football with a number of local schools, McCarthy joined the Saints in October 1963 and signed his first professional deal with the club in November 1965; he did not make his senior debut until two years later, against Sunderland on 25 November 1967.
[1] After Southampton's relegation to the Second Division in 1974, McCarthy struggled to regain his top form due to an operation on his knee, and after making only 16 league appearances in the 1974–75 season he decided to retire from the professional game at age 26.
[1] McCarthy spent a few seasons playing for local non-league clubs Poole Town, Cowes Sports, and Andover before retiring from football entirely.