1909–10 season he played in all but two of Rangers' matches. The following season he was ever-present as Rangers took the title and in 1911–12 he only missed one league match as Rangers took the title for the third consecutive year. Thus, in his first three seasons, he only missed three out of a possible 112 league games. He was considered to be on the reckless side, in terms of his own personal safety. A daring personality, he was expert at foiling forwards who had managed to run through on goal, leaving themselves "one on one" with the 'keeper. Invariably, just as the forward was about to shoot, Lock would throw himself at his feet to block the attempt. This recklessness resulted in several injuries during his career. Injuries sustained in a Glasgow Cup match against Partick Thistle on 7 October 1912 put him out for the remainder of the season. He was replaced by John Hempsey and was unable to reclaim his No.1 jersey until 17 January 1914. On his return he kept clean sheets in seven of his first nine matches but the team missed out on the title to arch-rivals Celtic. Over the next few years injuries, and war work in the Glasgow shipyards, meant that he was in and out of the team and it was not until the 1919–20 season that he was again able to play a full complement of matches. His form this season was blistering and he kept clean sheets in 20 of the 35 league games he played. This included a run of ten games without conceding a goal from 24 January to 20 March 1920 as Rangers once again took the title. Although he remained at Rangers until August 1921, he failed to appear for the first team in 1920–21 and returned to England. In his twelve years with Rangers he made a total of 266 appearances, keeping a clean sheet in 109 of those matches – a rate of 41%. Later career His return to England took him to London where he joined Queens Park Rangers in August 1921. His stay at Loftus Road was short-lived and the following year he returned to Southampton where he acted as cover to Tommy Allen. He made his first appearance for Saints for 14 years on 14 March 1923 in the FA Cup Fourth Round replay against West Ham United at Upton