After spending a few months in the reserves, Shelley was given his big chance in the first team when Arthur Andrews broke his leg in an FA Cup tie at West Ham in January 1920.
[2] He rapidly gained considerable repute as a consistent, reliable half-back in the "stopper mould", having the knack of smothering opposing forwards by his ability to anticipate and intercept through-balls.
[1] In 1920, the Saints were elected to the Football League Third Division for its inaugural season, in which Shelley missed only three matches, forming a good relationship with Bill Turner at left-half, with Alec Campbell or George Moorhead at centre-half.
[3] Under manager Jimmy McIntyre, Saints went one better in 1921–22, finishing equal on points with Plymouth Argyle but with a superior goal average, with Shelly and Turner both ever-present.
For the 1925–26 season, Saints appointed Arthur Chadwick as manager, but his arrival made only a moderate impact on the team's fortunes, finishing 14th in the table.
[8] With occasional spells on the sidelines, Shelley retained his place at right-half for the next two seasons, but for 1929–30 his appearances were more irregular with, first, Bradford and then Arthur Wilson taking over.
His success with the youngsters led to him being asked by manager George Kay to take over as first-team trainer following the retirement of his mentor, Bert Lee in 1935.
[11] At Anfield, Shelley was a part of George Kay's coaching staff, helping the Reds take the English Football League championship in 1946–47.