He won three consecutive Serie A titles with Inter and hopes his knowledge of Italian football will go some way to offsetting the unfamiliarity with his new players.
"Obviously it's a handicap that I've only been with the squad a day," the Italian added. "But I think in this case it's a group of players that know each other, that have been playing together for a while, so I'm lucky. And in football luck counts a lot so we'll see what happens. The advantage is that I know Juve well."
Galatasaray reached the quarterfinals of last year's competition, where it memorably beat Real Madrid 3-2 in the second leg in Istanbul, but went out 5-3 on aggregate.
However, it had a disastrous opening match this season, losing 6-1 at home to Real Madrid.
"We need to forget about the match against Real Madrid," Mancini said. "We have to think about the future starting tomorrow.
"My aims are to continue Terim's good work, continue to win, continue to go forward in the Champions League. We have five games, starting from tomorrow's, which will be very difficult, but we'll try to pass the group and then we'll see."
The match will see Mancini reunited with current Juventus striker Carlos Tevez, with whom he had a major fallout with when the Argentine refused to come on as a substitute in a Champions League match at Bayern Munich in September 2011.
After being told by Mancini that he'd never play for City again, Tevez went on unauthorized leave to Argentina and only returned to Manchester with three months to go that season after failing to secure a move away.
"I'm very happy to meet Tevez again because, apart from the time in which he took a holiday, we always had a great relationship," Mancini said. "We won three trophies at Man City, we made history together. He's a great footballer."