By Paul Clennam
Manchester United midfielder Anderson wants to leave the club at the end of the season due to fears that a lack of first-team football will put paid to his chances of playing for Brazil at the 2014 World Cup, Goal.com understands.
A number of South American clubs are interested in signing the 24-year-old, while Porto are also hoping to bring him back to the Estadio do Dragao on a loan deal.
United could even use Anderson as a makeweight in any potential move for Porto's highly-rated Colombian attacker James Rodriguez.
"Anderson is desperate to play for Brazil in 2014 and knows he needs some regular match time," a source close to the club told Goal.com.
"Sir Alex can't offer him the first-team football that he wants."
The Red Devils value the midfielder at between €18 million and €24m and would welcome a permanent sale, but do not envisage any of the interested parties being able to come up with the full amount.
A number of Brazilian clubs have used third-party sponsors to fund the signings of big-name players in recent years, most notably when Flamengo captured Ronaldinho from AC Milan in 2011.
But if that scenario does not materialise, United see a loan move back to Porto as the ideal situation for both club and player.