Which coach led Mainz 05 to their highest ever Bundesliga finish, while also having the shortest tenure of all Mainz coaches in the 21st Century?

1. His managerial career included spells in Norway, England, and Germany.
2. He was appointed in 2015 and was dismissed before the end of the year.
3. The team finished sixth in the Bundesliga in his only season.
4. He was a prolific goalscorer in his playing days.