Lock moved to Leicestershire in 1965, and was made captain for the following two seasons, taking the club to second place in the County Championship in 1967. In 1967/68 he was unexpectedly recalled by England because of an injury to Fred Titmus, and played in the last two Tests against West Indies. He was the last man called up to play for England who was not playing for a first-class county. Though not achieving any great success with the ball, he contributed to the cause in another way, by making his highest first-class score of 89 in the first innings of the final Test at Georgetown, Guyana. England had nine wickets down when the game (played over six days) finished, and claimed the series 1–0.