"It is hardly a surprise," said Ferguson, who sold Beckham to Real Madrid in 2003.
"Going to the United States does not get you the kind of football he is used to.
"It is not the right level of football, therefore coming back into the mainstream of the game is not a surprise.
"People have been edging towards that quite a while now."
LA Galaxy are still to sign off on Beckham's loan to the Rossoneri.