Manchester United manager Sir Alex Ferguson believes that players' agents have given footballers too much power, which has become bad for the game.

The emergence of agents has given players more control over their contracts and decisions on their future with their respective clubs.

"To begin with, when I first started out in management 37 years ago there were no agents. Imagine that!" Ferguson told FIFA.com. "There was no freedom of contract either, so players were totally tied to their clubs.

"A change in that sense was inevitable, though I think that now the scales tipped completely in the other direction and I'm not sure it's good for the game.

"Of course the way the media works has changed too, there's a lot of pressure on journalists to publish huge news stories, not just about sport but about everything, and that's had an impact on us, no doubt about it."

A recent high-profile case is that of Manchester City striker Carlos Tevez, who was able to jet off to South America for over three months without the club's permission.