The highly-rated Tuchel, 40, still has a year to run on his contract and led Mainz to seventh place and qualification for the Europa League this season.

But he made it clear a month ago he did not want to continue in his job next season, Heidel said.

That led to speculation he was being lined up to replace Jurgen Klopp at Borussia Dortmund, with Klopp - himself a former Mainz coach - linked with other managerial posts around Europe.

There were also press reports that he was in talks with Schalke 04.

But Mainz are not prepared to just let him walk away from the final year of his contract.

"As of today, our collaboration is at an end," Heidel said. "We certainly do not want any friction or an argument with him, there is no reason to quarrel, but there is absolutely no way we're going to tear up his contract."

Mass circulation tabloid Bild claimed he could either take over at Red Bull Lepizig, an ambitious Second Division club, take a sabbatical year or, should Germnay have a less-than-successful World Cup, find himself drafted in as a replacement for Joachim Loew.