At 16, But joined Borussia Dortmund from Chernomorets Novorossiysk. During his first season with the German club, But won the Champions League, but left the club after falling out with Matthias Sammer. In 2000, But joined Freiburg, where he stayed for the next three seasons, but yet again fell out with the coach and left Freiburg for Hannover 96.
He eventually returned to his hometown club of Chernomorets Novorossiysk.