Former England and Newcastle United boss Sir Bobby Robson has described Manchester City's £100 million offer for AC Milan star Kaka as "ludicrous".

"I am absolutely shocked by this, it is an unbelievable figure," said Robson.

"It is absolutely ludicrous because nobody is worth that amount of money, no matter what he does.

"I think bids like this will cripple football because it will carry on pushing the price of players up all over the world and there is not enough money in the game to cope with that."

The sentiment was echoed by former City manager Joe Royle, who questioned the morality of the potential deal.

"It's an incredible amount of money and you have to question the morality of it when the world is in a cash crisis," he said.