Born in Castrop-Rauxel, North Rhine-Westphalia, Kruska started his career at SC Arminia Ickern and soon signed for VfR Rauxel 08, the team from his native village.

On the final match day of that season, he scored his first goal against Hansa Rostock, making him the fourth youngest scorer ever in the history of the Bundesliga.

The three following seasons confirmed his place in the starting line-up as defensive midfielder, bringing his total number of Bundesliga games to 98.

After a half year and fifteen games in the Jupiler League for Club Brugge, he returned to Germany signing a three-year contract with FC Energie Cottbus on 28 July 2009.

In January 2018, Kruska left SC Paderborn 07 for league rivals Werder Bremen II.