One of the few natives of Cologne to play for Kölner Haie in the Deutsche Eishockey Liga, Krupp was spotted by Scotty Bowman, the coach and general manager of the Buffalo Sabres, who chose him as the 214th pick in the 1983 NHL Entry Draft. After Kölner Haie won the German Championship in 1986, the team released Krupp to allow him to play in the NHL. He made his NHL debut against the Montreal Canadiens, but spent the latter part of the season with the Rochester Americans of the American Hockey League, where he was a member of the Americans team that won the Calder Cup. Krupp scored an overtime goal in Buffalo's final game the 1989–90 season against the Pittsburgh Penguins that eliminated the Penguins from playoff contention.