Santos forward Neymar, 19, is rated as one of the finest young talents in world football and has been linked with a host of top clubs.
Chelsea attempted to sign the player last summer and, whiled they failed to agree a fee, their chief scout, Piet de Visser, confirmed last month that they were still interested.
Manchester City have also been linked, and Mancini was present at Sunday's friendly to take a look at the player first-hand.
And Brazil coach Mano Menezes believes Neymar would benefit from playing in the Premier League.
Menezes said: "I think that could only be good for Neymar as it would be confirmation of his development. English football would make him stronger and help to escape strong marking. I don't see any problem. But Brazil fans will be deprived of watching a good player."
Barcelona and Real Madrid are also said to be looking at Neymar but the player said in November that, of all the clubs that have expressed interest, he was most interested in signing for Juventus.
With Inter also said to be considering a bid, Neymar revealed in Gazzetta dello Sport on Sunday that he would relish the chance to play in Serie A.
"My objective is Italy, but also European football in general," Neymar said. "Anyone would love to play in Serie A, even if I am also happy at Santos."