This is a dress rehearsal for their June 21 World Cup group opener in Kayseri, but it could also decide which team from Group B advance to the third-place play-off of the Toulon Tournament on Saturday.
Portugal are on four points, same as Mexico, who they held to a thrilling 3-3 draw on Tuesday.
Nigeria are fourth in the standings on two points, but they could leap frog both teams if they beat their World Cup rivals and Belgium, who are bottom of the group on a point, upset defending champions Mexico.
Portugal are a very compact team who play for each other and they have strength in depth.
From their outings at the Toulon Tournament, they have shown they attack from the wings and are not shy to shoot from distance.
Against Mexico on Tuesday, Guinea-Bissau-born striker Alberto Gomes de Pina aka Aladje caught the eye with his vision, sweet left foot, skills and goal.
The 19-year-old striker from Italian lower league club FC Aprilia used his imposing size to great effect against a well organised Mexico defence.
It will also be interesting to see how Sporting Lisbon central defender Tiago Ilori, whose father is Nigerian, copes with the power and speed of the Nigerians.
The Flying Eagles, on the other hand, stepped up their game against world champions Brazil on Tuesday especially in the second half.