Keje Molenaar believes Martin Jol was a victim of Ajax's "lack of vision and leadership" and has called for changes in the wake of his exit.
Jol left the Amsterdam ArenA by mutual consent on Monday with the team fourth in the Eredivisie table, five points off leaders PSV Eindhoven.
The former Tottenham and Hamburg manager, who only took charge of Ajax in May last year, claimed the expectations at the club were too high.
Molenaar said: "Jol is yet another victim of the lack of vision and leadership within the organisation.
"Clearly it is important that there is a change. We should not look at the passers-by - they should not take the blame.
"I think we can do something serious and I am convinced that Ajax can then come good."
Former Holland defender Frank de Boer has taken temporary charge of team affairs until the winter break.
Ex-Ajax midfielder Edgar Davids yesterday backed De Boer to make a success of the role.
He said on Twitter: "Frank de Boer new coach of Ajax. He can do for Ajax what Pep Guardiola has done at Barca."
