He's only been gone a few days but already speculation is ramping up about Thomas Tuchel's replacement at Borussia Dortmund. Two Dutchmen are among the favorites and some familiar Bundesliga names are also in the frame.
Giovanni van Bronckhorst
The former Barcelona and Arsenal fullback (pictured, top) has impressed in his first management position at Dutch side Feyenoord, where he started and ended his playing career. The 42-year-old led the club to the Dutch Cup in his first full season in charge, before breaking their 18 year Eredivisie title last month. His work with youngsters like Tonny Vilhena will appeal to a Dortmund setup that has a stable of promising youngsters, while a playing career where he won 107 caps for the Netherlands is sure to command the respect of BVB's players.
A spanner in the works may be van Bronckhorst's loyalty to his current employers. He left Barcelona with a year left of his playing contract to re-join Feyenoord, after inserting a clause in his contract that meant he could leave for his boyhood club on a free and he may well opt to lead them back in to the Champions League.
The other Dutch coach among the frontrunners came to prominence as his Ajax side made the Europa League final, which they lost to Manchester United. As with his compatriot, his work with young players will have caught the eye of the top brass at BVB, with the likes of Kasper Dollberg and German winger Armin Younes to the fore in the Amsterdam club's European run.
Bosz has more experience than van Bronckhorst, having managed several other Dutch sides and Israeli outfit Maccabi Tel Aviv but is yet to capture a major trophy as a boss, something that may put the German Cup winners off.
Until Friday, Favre looked to be the man most likely to take Tuchel's place but a statement from his current club Nice, who overachieved in coming third in Ligue Un this season, was emphatic: "The club doesn't want to follow any negotiation concerning a transfer of its coach (who is) under contract until June 2019," said Nice. "This decision is firm and was fully heard by Borussia officials."
While that seems to have ruled the former Borussia Mönchengladbach coach out of the running, it could just be the opening salvo in some complex negotiations.
The youthful Hoffenheim coach is the hottest managerial property in German football after first saving Hoffenheim last season before leading them to the Champions League this term. At just 29, Nagelsmann doesn't have a wealth of experience but the attractive style he's introduced and the way he's been forced to cope with losing some of his better players (Niklas Süle and Sebastian Rudy agreed deals to Bayern during the season) may make him a good fit at Dortmund.
Despite his achievements, Nagelsmann is still considered an outsider, perhaps partly because he, like Van Bronckhorst, may want to enjoy the fruits of his labor by managing Hoffenheim in the Champions League.
The other German outsider has also enjoyed a surprisingly successful campaign with English side Huddersfield, who he led to an unlikely promotion to the Premier League after a playoff victory over Reading.
Wagner's trump card is perhaps his relationship with the club. Between 2011 and 2015 Wagner was Dortmund's second team boss when Jürgen Klopp was in charge of the first team.