Schalke general manager Horst Heldt has claimed Huub Stevens backed the decision to relieve him of his duties as coach of the club.
The Gelsenkirchen outfit enjoyed a record-breaking start to the Bundesliga season, but fell away in recent weeks, and the Dutchman was dismissed after a 3-1 loss to Freiburg on Saturday.
"First of all, I'd like to thank Huub Stevens for the work he has done," the 42-year-old told reporters at a press conference.
"He has always given his all for the club and acted in the interests of Schalke. However, after the performance against Freiburg we no longer had the necessary confidence that he could turn things round.
"I informed Huub of our decision at a personal meeting early on Sunday morning. He backs the decision."
He also introduced the Stevens' successor, Jens Keller, who formerly trained the club's Under-17, and is confident the former Stuttgart man will do a great job.
"He was immediately prepared to take on the job. I know Jens from my time at Stuttgart and am convinced he is an outstanding coach. He was a pro himself and has a wealth of experience.
"We hope he can deliver the impetus to get us back on track. We have every confidence in him."
"Before Christmas we have another tremendously important game against Mainz in the DFB-Pokal. The onus is on the players now. I expect everyone to conduct themselves in a professional manner."