The Brazil international moved to Old Trafford from the Portuguese giants for £17.5million in 2007.
He enjoyed a productive opening to his Red Devils career, but has suffered with injuries and a loss of form over recent seasons.
A reported bust-up with boss Sir Alex Ferguson during pre-season has seen him slip further down the pecking order, making just four appearances in all competitions this term.
The 22-year-old has now hinted that he may be prepared to move on in search of regular first-team opportunities.
He admits that a second stint at Porto would certainly appeal to him, but has given no indication as to when he would like to make such a move.
"I am good in Manchester but I'd like to return to Portugal and my preference would be Porto. I love the country," said Anderson.