A win would take Manchester City into the last 16 of the Champions League with a game to spare and their domestic form suggests that is well within their capabilities against the side already seven points behind the Serie A leaders.
City have looked unstoppable in the league, winning 11 out of 12 games and scoring 42 goals in the process,
However, manager Mancini knows as well as anyone that a match in Napoli is unlike anything they have encountered in the Premier League.
"My feeling is good because I think that our team has improved a lot in the Champions League but I know what we can find in Naples," the Italian said after Saturday's 3-1 win over Newcastle.
"Naples this season are playing very, very well at home and if we want to win in Naples we should play better."
The San Paolo was the scene of what is remembered in Italy as one of Mancini's finest goals during his Sampdoria career, a spectacular volley in a 4-1 win 1990/91, the season they won the Scudetto.
City, with seven points from four games, are second in Group A, three points behind leaders Bayern Munich who are expected to clinch their place at home to Villarreal the same evening.
Napoli, like City making their Champions League debut this season, have five points and must win to keep alive any realistic hopes of progressing.
City have not won in three previous visits to Italy while Napoli are unbeaten in 10 home matches since they returned to European competition following a 13-year absence which saw them drop down to the Italy's third tier.
In those 10 games, they have conceded only one goal, scored by Toni Kroos of Bayern Munich earlier in Group A.
Their last home European defeat was against Eintracht Frankfurt in 1994.
Napoli have been highly erratic this season and their Uruguayan striker Edinson Cavani has been a shadow of the player who scored 26 Serie A goals last season.
But when Cavani hits form, as he did by scoring a hat-trick in the 3-1 win over AC Milan in September, Napoli are a different proposition.
"It won't be at all easy, as City are a team of phenomenal players," said Napoli coach Walter Mazzarri. "But we will go to the bitter end."
Mancini, who has been rotating a squad bristling with international players, rested Edin Dzeko on Saturday and the Bosnian should head the attack.
Mario Balotelli could be preferred to partner Dzeko in his homeland thanks to a goal-scoring record and a cool-as-a-cucumber attitude that is making him a fan favourite.
Napoli: 1-Morgan de Sanctis; 14-Hugo Campagnaro, 28-Paolo Cannavaro, 6-Salvatore A
