Sir Bobby Robson believes ''no manager worth his salt'' will be interested in succeeding Kevin Keegan at Newcastle unless there is fundamental change at St James' Park.
Former Newcastle manager Robson, who was sacked in August 2004, insists he will not boycott the club as some supporters plan to, and he intends to attend the next home Premier League match against Hull next Saturday.
But Robson believes the ''all-powerful'' presence of executive director of football Dennis Wise on the Newcastle staff has been a major part of the problem which came to a head when Keegan quit as boss on Thursday.
Robson, the former England manager, claims any manager must have a major say in signings and the identity of anyone appointed to work with him, in a role such as Wise's.
He told the Mail On Sunday,''The breakdown between the different job titles has left Newcastle in disarray and it is time for Mike Ashley to sort it out. The owner or chairman is the most important person at a football club, the manager is second and everyone else third.
''If a director of football does not have the blessing of the manager, it does not work.''
When Keegan announced his resignation, he stressed it was his belief that managers ''must have the right to manage'' and must have the final say on any incoming players.
He may have known little of the moves which saw Xisco and Nacho Gonzalez come to the club on Monday, and Robson said: ''You cannot imagine Sir Alex Ferguson, Arsene Wenger or Rafa Benitez being handed players they did not know anything about. And no manager worth his salt is going to take the Newcastle job with the current set-up.''
Robson is convinced the presence of Wise at Newcastle will remain unsettling, particularly if he continues to spend much of his time in London, and he has questioned the former England midfielder's credibility, citing his lack of top-flight experience as a manager.
Robson added: ''It is no surprise that Kevin Keegan left this week. For a proud manager like him, it must have been impossible to work under the control of Dennis Wise. First of all, the director of football was more powerful than the manager, which should never be the case. And secondly, they did not work in unison, which means communicating face to face. How could they, when Kevin was there at the club, and Wise was not?''