The 34-year-old has been with United since 2002 and Ferguson believes that Ferdinand is proving that he has longevity with an impressive season for the Red Devils.
He said: "Rio has had a great season. Obviously he doesn't play every game but we prepare him for certain situations.
"Defenders, if they look after themselves, should have longer than Giggs and Scholes because they don't have the mileage on the clock that midfield or wide players have.
"There is nothing wrong with us giving players one-year contracts. Players with the reputation and ability of Giggs, Scholes and Ferdinand should not worry about that. It is quite straightforward."
Ferdinand has made 20 appearances for United so far this season.