Multiple sources are reporting that Youri Baas is the subject of an offer from Porto, who have made a move to sign one of their top transfer targets. The defender, currently at Ajax, is now at the centre of negotiations between the two clubs - while it remains to be seen whether the opening offer will be enough for the team to part with their man. Until a fee and conditions are finalised, the deal remains vulnerable to disruption - especially if Crystal Palace, Newcastle and Real Madrid decide to make a formal offer of their own in the coming days. Ajax continue to be linked with Sofyan Amrabat, Moriba Ilaix and Viktor Tsygankov while Porto are also rumoured to be tracking Quinten Timber, Diogo Leite and Mohamed Toure. Can't get enough Porto transfer rumours? Follow @PlayerSwitchCom on Twitter for the latest transfer news as it happens.