Ronaldo failed to get on the scoresheet, but helped Juventus win 3-2 at Chievo on Saturday.
D'Anna reflected yesterday: "Ronaldo is as strong as when you see him on TV, an extraordinary player, off the charts, but Juve is not just Ronaldo.
"Their quality is stratospheric.
"With Ronaldo, he has the mentality of the champion, he is a player who moves to unbalance, a great asset for Italian football.
"Not since the time of Inter and Ronaldo have we seen this. In Italy there has not been a player of this calibre since then."