Keegan had become disillusioned with a structure which took player recruitment and sales out of his hands and placed them in those of executive director (football) Dennis Wise.

Alan Curbishley also left West Ham a day earlier citing similar reasons, and Barnes, who had a brief spell in charge of Celtic, believes managers should always have the final say when it comes to the make-up of their squad.

“For me, I wouldn’t like to be a manager under those circumstances as when things go wrong it’s the manager who usually suffers by losing their job,” he told www.footballpools.com.

“If this system is to work then the role has to be defined with clarity as at the moment there is no standardised role.

“It would seem that both Keegan and Curbishley feel they were misled in the roles their directors of football were playing.

“This system can work if the man in that role acts as a go-between for both manager and board such as Avram Grant at Chelsea, but as soon as the director of football begins meddling in the comings and goings of the playing staff at the club, then no manager would be happy with that unwelcome input.

“Managers identify players that fit into their tactics and playing philosophy so ultimately signings have to be their choice.”