Andrew McLaren was born in Larkhall, Scotland on 24th January, 1922. He joined Preston North End just before the outbreak of the Second World War. The government imposed a fifty mile travelling limit and the Football League divided all the clubs into seven regional areas where games could take place. At the age of eighteen Scott became a regular in the side.
In the 1940-1941 season Preston North End needed to win their last game against Liverpool to win the North Regional League title. The nineteen year old McLaren scored all six goals in the 6-1 victory. It has been argued by Jack Rollin (Soccer at War: 1939-1945) that: "The first club to benefit from a youth policy to any marked degree was Preston North End, who owed success in 1940-41 to their exceptional pre-war structure. By 1938 the club was already running two teams in local junior circles when the chairman James Taylor decided upon a scheme to fill the gap between school leavers and junior clubs by forming a Juvenile Division of the Preston and District League open to 14-16-year-olds."
Rollin points out that by 1940 over 100 youngsters were being trained in groups of eight of the club's senior players voluntarily assisting in evening coaching. Robert Beattie was one of those involved in this coaching. The first youngsters to emerge from this coaching system included Andrew McLaren, William Scott and Tom Finney.
Preston North End also took part in the 1941 Football League War Cup. McLaren scored five of the goals in Preston's 12-1 victory over Tranmere. He also scored a hat-trick in the fourth-round tie against Manchester City. Preston reached the final by beating Newcastle United 2-0. The Preston team that faced Arsenal at Wembley on 31st May was: Jack Fairbrother, Frank Gallimore, William Scott, Bill Shankly, Tom Smith, Andrew Beattie, Tom Finney, Andrew McLaren, Jimmy Dougal, Robert Beattie and Hugh O'Donnell.
The game took place in front of a 60,000 crowd. Arsenal was awarded a penalty after only three minutes but Leslie Compton hit the foot of the post with the spot kick. Soon afterwards Andrew McLaren scored from a pass from Tom Finney. Preston dominated the rest of the match but Dennis Compton managed to get the equaliser just before the end of full-time.
The replay took place at Ewood Park, the ground of Blackburn Rovers. The first goal was as a result of a move that included Tom Finney and Jimmy Dougal before Robert Beattie put the ball in the net. Frank Gallimore put through his own goal but from the next attack, Beattie scored again. It was the final goal of the game and Preston ended up the winners of the cup.
McLaren continued to play for Preston North End during the Second World War. In April 1947 he won his first international cap when he represented Scotland against England. McLaren scored Scotland's goal in the 1-1 draw. He also scored two against Luxemburg (May, 1947) and one against Wales (November, 1947). However, after scoring four goals in four games he was dropped and never played for his country again.
McLaren was Preston's top scorer with 17 goals in the 1947-48 season. He was surprisingly exchanged for John Knight of Burnley in 1948. McLaren found it difficult to settle at his new club and moved on to Sheffield United. He also played for Bradford Park Avenue, Southport and Rochdale before retiring from football.