According to O Jogo, City scouts were in attendance as Benfica took on Napoli in the Champions League.
And the Portuguese newspaper has reported that they were keeping a close eye on Benfica goalkeeper Ederson, who has been strongly linked with a move to the Etihad.
The 23-year-old Brazilian has impressed since breaking into the Benfica first team last year, and he has made seven league appearances so far this term.
He has also been a regular in the Champions League and Tuesday night's 2-1 defeat to Napoli was his fifth appearance in the competition this season.