The 20-year-old made his senior bow for the Selecao's senior side earlier this month in their 5-0 win over El Salvador.
Militao, who can fill it at right-back, centre-back or in defensive midfield, has seen his price tag climb to £17m after his breakthrough at international level.
Brazilian outlet UOL suggests that Everton are still tempted to make a move for the highly-rated youngster, however, having sent scouts to watch him twice in the space of a week.
Toffees chiefs are said to have been in attendance for Porto's 1-1 draw with Schalke in the Champions League and the 2-0 win over Vitoria Setubal four days later, with Militao playing a full part in both matches.
Despite only arriving at the Estadio do Dragao in August on a five-year deal, the report claims that the Sao Paulo academy product could be on his way out next January if the right offer is tabled.