While serving as a Royal Air Force navigator during the Second World War, Liddell continued his career by appearing in unofficial games for Liverpool and guesting for various teams in the United Kingdom and Canada.

Primarily a left winger, Liddell's versatility enabled him to play comfortably on the opposite wing and as a striker, at centre and inside forward.

[8] Posthumous recognition has included a plaque unveiled in 2004 at Anfield and sixth place in a poll of Liverpool fans, conducted in 2006 under the title "100 Players Who Shook The Kop".

He became a reluctant rugby player, under the guidance of retired Welsh international Ronnie Boon, while playing football for local teams and Scotland Schoolboys.

[9] By the age of 16, Liddell had progressed sufficiently to earn a contract with Lochgelly Violet football club and be sought after by Liverpool, Hamilton Academical, and Partick Thistle.

Liverpool manager George Kay became interested in signing Liddell on the recommendation of the club's Scottish halfback Matt Busby, who learned of the teenager from Manchester City's Alex Herd while on a golf trip.

He subsequently moved to Northern Ireland for further training, where he declined an offer from former Liverpool goalkeeper Elisha Scott to guest for Belfast Celtic because of a prior agreement to play for Linfield.

The match ended in a 2–0 win and featured several additional debutants,[22] including Bob Paisley, who would forge a chemistry with Liddell as a left half.

Positioned on the left wing, he appeared in 34 matches, scored seven goals,[5] and supplied strikers Albert Stubbins and Jack Balmer with numerous assists.

The club won its final game away against Wolves 2–1, with Liddell setting up one of the goals,[27] but the championship was decided by Sheffield United defeating contenders Stoke in the season's last fixture.

[30] His displays against Sweden's Djurgården, played at the Brooklyn Dodgers' Ebbets Field, and North American teams earned him praise from journalists and gained him 13 goals in 11 matches.

Restrictions in England limited the weekly wage (£12 in the season and £10 during the summer) and impeded a player's ability to transfer to another club, which caused much discontent in British football until the system was reformed in the 1960s.

[46] The club again underperformed in the 1951–52 season, in which Liddell scored a goal against Huddersfield Town described by contemporary media as the "shot of a lifetime" and reported in detail by the Liverpool Echo.

Baron passed it to Liddell, who struck the ball with such force, after a momentary pause, that the shot surprised the Huddersfield defence and goalkeeper Harry Mills, and silenced spectators.

[53] To confound the sporting media, Liverpool went on to defeat Everton 4–0 in January, in an FA Cup fourth round fixture at Goodison Park before a crowd of 72,000.

Seconds before full-time, Liverpool dispossessed City and Liddell advanced from the halfway line to Bert Trautmann's goal, striking in the penalty box, reportedly just as the referee signalled to end the match.

Along with Trautmann and many other players,[58] Liddell had been unaware of the full-time whistle and Liverpool's supporters stayed in expectation of extra time until an announcement informed them of the scoreline.

While injuries to Louis Bimpson and Brian Jackson meant Liddell played much of the season as a right winger and inside right, he retained his place as the club's leading scorer, with 21 goals.

[60] Promotion again eluded the club in the 1957–58 season,[61] while Liddell surpassed Elisha Scott's record of 430 league appearances (then erroneously believed to be 429) in November 1957 to acclaim.

In recalling the match against Notts County, which it transpired only equalled the record, Liddell confessed to having felt self-conscious because of the attention that he received, while appreciative of the respect shown to his achievement, especially from his opponents, managed by friend Tommy Lawton.

[63] After one start in November, Liddell returned to the senior squad in March 1959 for his 466th league appearance, which the footballing community believed would surpass Ted Sagar's Merseyside record of 465.

He completed the next match, against Plymouth Argyle, and played in ten successive games, scoring his final goal for the club in a 5–1 defeat of Stoke in March.

He gained his first full cap against Switzerland scoring twice in a 3–1 win at Hampden Park on 15 May 1946[2] At international level, Liddell played predominantly as an outside left, in competition with Scotland-based Lawrie Reilly and Willie Ormond.

[75] The Scottish Football Association (SFA) denied Liddell and his teammates the opportunity to participate in the 1950 World Cup, hosted by Brazil, because of an earlier decision not to sanction involvement as British Home Championship runners-up.

[82] He scored his last goal for Scotland in an ill-tempered 4–1 win over Austria at Praterstadion, where a brief pitch invasion involving large numbers of supporters reportedly resulted in altercations between players and fans.

"[90] After retiring in 1961, Liddell served as assistant permanent secretary and bursar to the University of Liverpool Guild of Undergraduates (Student Union) until 1984,[91] and authored a memoir, titled "My Soccer Story".

[91] More than 10,000 people watched Liddell play opposite retired Hungarian international Ferenc Puskás at South Liverpool's Holly Park ground, raising £1,100 in the process.

[97] Liddell's biographer John Keith, who also presented on BBC Radio Merseyside, had proposed the memorial to then chairman David Moores and chief executive Rick Parry.

[98] Further recognition came in 2006 when Liddell attained sixth place in a poll of more than 110,000 people conducted by Liverpool's official website to determine a list of "100 Players Who Shook The Kop".

[99] When Liverpool approached former players to identify their personal favourites as a complement to the list, Ian Callaghan, Tommy Smith, David Johnson, and Roy Evans included Liddell in their "top five".