City have a relatively poor record against Sunderland in recent times, winning just one of the last five meetings between the two sides.
The last two meetings have seen the Black Cats grab a dramatic late win which threatened to derail City's title bid last season and a late comeback from 3-1 down for City to rescue a point, and Mancini knows all too well that Sunderland will be no pushovers.
"It is very difficult because every time Sunderland play against us they play a fantastic game," said the Italian.
"Last year the point we got against Sunderland after we were 3-1 down with five minutes to go, and we equalised in the end with [Aleksandar] Kolarov, was an important point in the league."
City currently sit fourth in the Premier League table, while Sunderland are down in 13th with a game in hand.