AC Milan are looking to tempt Manchester United defender Nemanja Vidic into making a summer switch to Italy, while Eliaquim Mangala admitted to being flattered by reports linking him with a move to Old Trafford.

Vidic has been the backbone of United's defense for several seasons now; but the past couple of years, injuries, particularly to his knee, have seriously slowed down the Serbian's progress.

The 31-year-old has been sparingly used by Sir Alex Ferguson this season, and with United looking at bringing in a central defender in the summer, doubts have been cast over the veteran's long-term future with the club along with that of Rio Ferdinand.

Vidic will only have one year remaining on his contract at the end of the season, and Milan are reportedly keen to take advantage of that situation, making the Serbian international their No.1 target for the summer, according to Goal.com.

Ferguson will only listen to offers of above £10 million ($15 million) for the Serbian international, with Milan reportedly ready to match that fee.

It is unlikely that Vidic will be let go at the end of the season, with the 31-year-old still seen as key to United's fortunes by Ferguson. Milan are also extremely unlikely to pay £10 million for a player over thirty, as they look to build their team on youth.

Meanwhile, another central defender who has been linked with a move to United in the summer - Mangala - said he was happy to interest the likes of United, but said any move would have to satisfy his current club Porto.

"I am definitely flattered by the interest of such a big club like Manchester United, any player would be," he told Sky Sports.

"I have a contract here until 2016 so even if I want to go, Porto will have their say in the transfer."

The 22-year-old, who started his career at Standard Liege before making a move to Porto in 2011, is very highly rated in Portugal and has been tipped for big things in the future.