[3] Despite being aged just 16, he made his professional debut in a league match versus Olimpia Poznań on 5 June 1977, coming on as a substitute for Andrzej Głownia after 67 minutes.

[3] Kruszyński travelled with the club to take part in a friendly tournament in West Germany in the summer of 1979 and refused to return to Poland with the team, which caused the Polish FA to suspend him for a year.

[3] In a three-season spell, he failed to make an appearance for the club's first team,[3] but trained with high-profile players Franz Beckenbauer, Kevin Keegan, Manfred Kaltz and Felix Magath.

[7] Kruszyński made 32 appearances to help Saarbrücken to a third-place finish in the 1984–85 season and though he did not play, the club secured promotion to the Bundesliga after winning a playoff versus Arminia Bielefeld.

[8] Kruszyński moved to England to sign for First Division club Wimbledon in December 1988 for a £100,000 fee and he became the third Pole to play in the English top-flight.

[11][12] Kruszyński signed permanently for a £60,000 fee in August 1992,[9] but managed only eight appearances during the whole of the 1992–93 season,[11] as the Bees suffered relegation straight back to the third tier.

[12] Kruszyński failed to see eye-to-eye with manager Phil Holder and was transfer-listed in September 1992, before being fined two weeks' wages for a training ground bust-up with coach Graham Pearce later in the year.

[11] After a deal to move back to Germany fell through,[13] Kruszyński remained in England and signed for Premiership club Coventry City in September 1993.

[3] Kruszyński's decision to play club football in Germany in 1979 effectively ended his international career, due to citizenship issues.