New Newcastle boss Sam Allardyce has admitted that even if he spent £100million it would not be enough for instant success on Tyneside.
But the Magpies boss is fully aware that Mike Ashley will not tolerate failure after spending almost £100m to take over the club.
And Allardyce has said he would expect the sack if he does not turn things around at St James' Park.
Allardyce told The Chronicle: "Everyone wants instant success but this is a recipe for disaster.
"In fact, the club has been a disaster in terms of success in the last 10 seasons, and if you want that you aren't going to get that from me.
"There is too much to do to have instant success here, even if we spent £100m.
"We have to put in completely new ideas and a complete new structure behind the scenes and then you have to sell at this to the players which takes time.
"My job relies on winning football matches at first-team level.
"So I will adjust everything accordingly to make sure every game we go out and play and give myself enough time.
"The only time I will get is by winning football matches, not losing them - I know that I won't get any time if I lose them.
"I will then be a casualty like everybody else has been a casualty over the past few years.
"I know the responsibility and I know the only way to make the time I need is to get the results everyone wants as quickly as we can.
"But it cannot always happen. The long-term and the growth of the club is what needs to be tackled now."