The Red Devils boss already has an eye on next season with the signing of young Mexican striker Javier Hernandez confirmed on Thursday.
"It is about getting the player we need who are going to improve us or maintain the level we are at," Ferguson said.
"That is the way we have operated in the past and there is not a lot wrong with that policy.
"There is conjecture about every player. Last summer it was Franck Ribery and Karim Benzema, although he was a young player and one of the targets we set out to get.
"Now it is David Villa.
"I am sure by the end of the season there will be half a dozen more. I can't confirm that speculation but most of it is not right."