[1] Blockley was born in Leicester but began his career with Coventry City, making his debut for them in the 1968–69 season.
[3][4] Towards the end of his first season, and playing despite an injury, Blockley's uncertainty in the FA Cup semi-final against Sunderland contributed to Arsenal's defeat, and his relationship with the supporters never really recovered.
However, with Frank McLintock leaving Arsenal in the summer of 1973 Blockley became first choice centre back, and early in the 1973-74 season he scored his only league goal for the Gunners, versus Leeds United.
However, the season was to turn out to be a difficult one for both Blockley and Arsenal, with defeats in both domestic cup competitions to lower-level sides.
[9] After retiring, Blockley did not opt for a career in coaching or management and instead became a salesman for a power transmission company.