Silva, who joined City from Valencia in the summer of 2010, scored two goals and created one in Alicante as the reigning European and world champions marched on to a 3-1 victory in their Euro 2012 Group I qualifier.
The 25-year-old has been in good form for City in the Premier League as well this campaign, scoring twice and providing five assists in seven matches, leading Mancini to heap praise on him.
"Silva is one of the best players in the world," said the Italian. "There is no doubt about that.
"He played very well against Scotland and scored two goals and has thankfully come back okay.
"He is an excellent player who has improved a lot in the last year and, obviously, I hope that improvement continues."
City are currently level on 19 points with rivals Manchester United at the top of the table after seven rounds of matches, and host Aston Villa at the Etihad Stadium on Saturday afternoon.