Mbemba’s first-team chances at Newcastle were limited last term, with Rafael Benitez favouring other options.
Florian Lejeune and Jamaal Lascelles formed Newcastle’s first choice centre-back pairing, and they both were rock solid throughout the back end of the campaign.
Lejeune and Lascelles look likely to go into next season as Newcastle’s central defenders, which has made Mbemba available.
Newcastle are looking to raise funds by selling their fringe players, and Porto are said to be keen to be the Congolese defender.
The Magpies are said to be discussing a £5 million transfer with Porto, with Mbemba very keen to leave St. James’ Park to join the Portuguese giants.
Mbemba has been at Newcastle since 2015, and has made 58 appearances for Benitez’s men.