He graduated through the reserves, making his first team debut on 1 February 1975 in a 3–0 victory away to West Bromwich Albion in League Division 2.
The following season, Saints had signed Peter Rodrigues and Andruszewski was to make only a handful of appearances in the first team, and did not figure at all in the squad who went on to win the FA Cup on 1 May 1976.
On 5 March 1977, he scored the winner against Charlton Athletic, when he crashed a shot past the keeper after running on to a return pass from Mick Channon.
In the 1977–78 season, he was selected fairly regularly including appearing in the final 13 games as Saints finished as runners-up (to Bolton Wanderers) to gain promotion back to Division 1.
In the season 1982–83, he signed for Aldershot, and then returned to the US to join the Houston Dynamos for the summer of 1984, and then the Dallas Sidekicks indoor soccer team from November 1984 to May 1985.