He said: "If a billionaire owner is going to come in and only give a manager money, it won't be enough. It really needs to be tagged along with time and three or four years to do it.
"But when people come in and spend big money, sometimes it becomes a situation where there has to be an instant hit.
"It's an impossible situation because nobody given the money can make it all gel and work straightaway. You need time and the chance to see it through.
"If you give somebody £100million, I don't know if that will get you in the top four in the Premier League next season.