Career
Kruska started his career at South Carolina Arminia Ickern and soon signed for VfR Rauxel 08, the team from his native village. In 1999, age 12, he was spotted by Borussia Dortmund and at the Westfalen Stadium he enjoyed his further training. Just 17, he made his debut in the first team against Kaiserslautern in 2004-2005.
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.
As the best U18 player, he was also awarded the "Fritz Walter Medal". 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 and signed on 28 July 2009 a three-year contract with Football Club Energie Cottbus. On 3 January 2014, he joined FSV Frankfurt.
Club Individual.