Schalke 04 cleared Magath in a statement over accusations by club president Clemens Tönnies that he had organised transfers without the permission of the board of directors.
However, Schalke did not clarify whether they were going to pay 57-year-old Magath compensation for sacking him on Wednesday, which could be as much as €12 million.
Magath, who guided both Bayern Munich and VfL Wolfsburg (who he rejoined on Friday) to the Bundesliga title, was sacked because of his transfer policy and his authoritarian treatment of the squad.
Magath guided Schalke to second in the Bundesliga last term and though they have struggled in the league this season - they are 10th, 28 points behind leaders Borussia Dortmund - they are in the German Cup final, having beaten holders Bayern Munich in the semi-final.
They are also the only German club still in the Champions League where they play holders Inter Milan.