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.
