Manchester United boss Sir Alex Ferguson can understand why Kevin Keegan couldn't resist returning to Newcastle.

He said: "He was working in Glasgow at his soccer school and has obviously been well out of touch with the game while he was trying to make it work.

"He was living a great, peaceful lifestyle. But, as soon as that phone went, a part of him must have thought 'There's unfinished business here'.

"It's excitement and we all need that in our life. And, for Kevin, the only source that could have come from was Newcastle.

"Kevin has a big challenge for himself."