The Turkish giants managed to fight back with an 89th-minute equaliser scored by Umut Bulut, but Mancini believes that the decision to penalise Nordin Amrabat for a foul on Fabio Quagliarella changed the match.
He told Sky Sport Italia: "I got to know my players a bit more, as I didn't know all of them well. I knew this would be a tough game because Juventus are a great squad
"It was a strange game, as Juve went behind and they were awarded a penalty that was, shall we say, strange? I think without that they would not have been able to score tonight. I don't think it was a penalty.
"Drogba was incredible and in all honesty I didn't expect him to play like this. He was extraordinary. The first half went well, but after the break we lost something in terms of stamina and Juve were able to pin us back more."