Ajax have announced that Marcel Keizer and his assistant coaches Hennie Spijkerman and Dennis Bergkamp have been “removed from active duty”, with former Holland defender Michael Reiziger to take over on an interim basis.

Keizer, who replaced Peter Bosz as manager in the summer when he left to join Borussia Dortmund, has taken Ajax to second in the Eredivisie but they were knocked out of the Dutch Cup on penalties by FC Twente on Wednesday having previously lost out in the preliminary rounds of both the Champions League and Europa League.

“The club management does not have enough confidence that the ambitions of Ajax will be realised with them,” read a statement on the club’s website on Thursday. “The disappointing sporting results are also the reason for this decision. With Dennis Bergkamp, there is also a difference of opinion about the technical policy to be implemented.”

Edwin van der Sar, the general manager, said: “We had a bad summer and a messy start to the season. From a sporting point of view, European elimination was the low point. In particular [sporting director] Marc Overmars and I have frequently spoken the months afterwards about the permanent volatility of the first team. We are not confident that we will achieve the level that we are striving for with Ajax in this way. I regret this. Together with the supervisory board, we as management are grateful to Marcel, Dennis and Hennie for their efforts for the club.”

Bergkamp has been at Ajax since 2011 and worked as an assistant to Frank De Boer before moving into a role working with the club’s young players last year. Reiziger, who played for Ajax in the 1995 European Cup final victory before spells at Milan, Barcelona and Middlesbrough, has been working as a coach with the club’s youth sides and will be assisted by former Holland team-mate Winston Bogarde for Saturday’s meeting with Willem II.