Sam Allardyce believes Newcastle need to give manager Kevin Keegan more time in the hot-seat before opting for a change in direction.
Keegan is back at the Magpies' helm after former Bolton boss Allardyce was sacked by owner Mike Ashley in January.
With Keegan making an inauspicious start to his second spell in charge of Newcastle, question marks have already surfaced over his future.
"Newcastle are destined to be a great club down the line," said Allardyce in the Times.
"But the longer it goes without success the harder it is to achieve it and they can't do it by changing managers all the time.
"I've no real bitterness over my departure anymore. I've moved on.
"We were finding a way of playing, having changed everything behind the scenes.
"The players were still learning to blend. It was a question of patience.
"It is like building the Empire State Building in a month. It can't be done."