The Serie A side are part of a tough Group E that includes the domestic league champions of Germany, Russia and England in Bayern Munich, CSKA Moscow and City.
Roma started their Champions League campaign with a thumping 5-1 of CSKA, but should face a decidedly more difficult task at the Etihad Stadium.
Head coach Garcia is not shying away from the challenge, though, and believes his team are well capable of competing.
"We have three points, we have started well and we will have the chance to play without pressure," Garcia said.
"After the draw, everyone took this game as a defeat, so we only have to gain from going to the Etihad.
"Are we third favourites to advance? Do not forget that at the draw we were in the fourth pot, not the third. It means that we are the outsiders, as we are facing the champions of Germany and England.
"We have this role as the outsider, but it can give us pride in being able to then demonstrate that the assessment of our team should be greater."
Asked whether three points would leave them in pole position to qualify for the knockout stages, Garcia responded: "This is only the second game. This phase will not be finished tomorrow.
"If tomorrow we were able to have more points it would be an interesting step forward in qualification.
"Concerning a positive result, I don't want to think about it, whilst there are also a further 12 points to be awarded.
"Champions League games are very easy to prepare for, because I do not need to motivate the players."