The People says the 27-year-old Colombian star was watched recently by United coach Phil Neville against Holland.
And Old Trafford scouts have seen the pacy South American in several Champions League games for Milan this season.
Zapata has become a key member of the Colombian national side who have climbed to fourth in the FIFA world rankings and are tipped to be a force at the 2014 World Cup in Brazil next summer.
He figures at centre-half for Milan and his country but can also play at full-back.
Worried about World Cup accommodation prices? Then check out the Favela Experience - the answer to your problems!