According to the same source, the Portuguese giants have tabled a bid of €15 million for the two rising stars of Argentine football.
It is believed they have offered €10 million for Centurion plus another 20% of a future sale, while also bidding €5 million for Farina.
The plan is to sign Farina in the January transfer window, with his teammate arriving next summer.
Everything suggests Racing Club chiefs will seriously consider the offer and get back to the Eagles in the coming days.
Ricardo Centurion, 19, has been followed by a number of top European clubs, but none of them were willing to offer more than €9 million for his services.
Luis Farina, 21, is an attacking midfielder who has been showing a lot of promise, although he has yet to establish himself as a first team regular at Racing.