Sir Alex Ferguson believes Rio Ferdinand could carry on playing longer than Ryan Giggs © PA Photos Enlarge

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Manchester United boss Sir Alex Ferguson believes the club's offer of a one-year contract extension for Rio Ferdinand is an insurance policy for his side, not a reflection on the defender's quality.

Ferdinand, 34, has reportedly attracted interest from clubs in the US and the Far East, although he is hopeful of remaining at Old Trafford next season.

The former England international's contract with the club expires at the end of the season and although Ferdinand could look abroad for a longer term offer, Ferguson believes a one-year extension is sufficient for veteran players.

"There is nothing wrong with us giving players one-year contracts,'' he said. "Players with the reputation and ability of Ryan Giggs, Paul Scholes and Rio Ferdinand should not worry about that. It is quite straightforward. It is not to say we doubt them but it is natural you never know how they cope with getting older. Some do, some don't."

Ferdinand has had a relatively injury-free run of late and became a critical part of United's defence early in the season, particularly in the absence of Nemanja Vidic. Although it is obvious that United will not guarantee Ferdinand's future at the club, Ferguson insists the former West Ham defender could have greater longevity in his career than 39-year-old Giggs and 38-year-old Scholes.

"Rio has had a great season," Ferguson said. "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."

Ferdinand could face former team-mate Dimitar Berbatov when Fulham travel to Old Trafford for an FA Cup fourth round tie on Saturday, raising questions about the Bulgarian's time at United. Berbatov became the club's most expensive purchase when he secured a move to the league leaders from Tottenham in 2008 for more than £30 million, but was regarded as a flop despite scoring 57 goals in 149 appearances for the club.

Ferguson omitted Berbatov from his squad for United's 2011 Champions League final against Barcelona, although he denies the striker failed to live up to expectation.

"That was very difficult," Ferguson said. "I felt if we needed a goal in the latter part of the match Michael Owen would be a better option. That was it. Straightforward. It was a terrible decision to make though and he didn't take it well, which is what you would expect because everybody wants to play in a cup final.

"I don't think Dimitar was a failure here. Some people like to see players run through brick walls all the time. Dimitar is not that type of player, but he is a very talented player and he had a decent goalscoring record here."

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