In 1990, the team joined the semi-professional Canadian Soccer League as the Kitchener Spirit.

[1][2] During their debut season, they set a league record for goals scored in a game with an 8–1 victory over the London Lasers.

[3] They finished fourth in their division, advancing to the playoffs, where they defeated the Toronto Blizzard in the first round in penalty kicks before falling in the semi-finals against the Hamilton Steelers.

[6] The club failed to make the playoffs, winning only four matches amid rumours of financial instability.

[4] The Kitchener–Waterloo region was without a professional team since the Kickers departed in 1991,[7] until SC Waterloo Region joined the later Canadian Soccer League in 2011, while K–W United FC played in the pre-professional Premier Development League from 2013 until 2017.