Manchester United scouts were in attendance at San Siro on Sunday.
TMW says United representatives saw Napoli defeat Inter Milan 1-0 - with Jose Callejon hitting a first-half winner.
The subjects of their attention were Inter winger Ivan Perisic and in-form Napoli striker Dries Mertens.
Both attacking players have been linked with United in recent weeks.
It proved a happier day for Mertens, with Perisic starting the game on the bench.