The Italian admits his side's 1-0 defeat in Denmark was a damaging result but believes they were unfortunate not to take maximum points
The Turkish side could have put a four-point gap between them and the Bianconeri going into the final two rounds of fixtures, but instead sit level with the Danish competitors and just one point clear of bottom-placed Juve after losing to Daniel Braaten's goal on Tuesday.
"The result is bad, but I don't think we deserved this defeat, if anything we deserved to win," Mancini told reporters after the match.
The Italian, who took over from Fatih Terim at the end of September, defended his choice of players for the meeting in Denmark and praised his side's second-half showing after they conceded early on in the match.
"I preferred to play Ceyhun Gulselam, when you're a goal down you don't have to be attacking your opponent with five strikers. We didn't give any chances to our opponent in the second half anyway. In the second half we were really good," he added.
"We didn't miss [Fernando] Muslera today, Eray [Islan] played well. [Wesley] Sneijder is one of our leaders. But we had chances even without him. We played well today. Never mind defeat, we definitely deserved to win."
Galatasaray's next European encounter is at Real Madrid on November 27 before hosting Juventus on December 10 at the Turk Telekom Arena in what looks set to be a crunch match for who will finish second in Group B.