Roberto Mancini's men have been tipped to challenge for the trophy in their first season in Europe's premier club tournament, but Rafinha thinks they will have to work hard just to get to the last 16.
City were held to a 1-1 draw by Napoli in their Champions League opener at the Etihad Stadium and on Tuesday face Bayern, who beat Villarreal 2-0 away from home last time out.
Brazilian defender Rafinha expects a tough game but is confident Bayern can carry on a blistering run of nine consecutive victories in all competitions.
"Bayern are in a good moment and now we want to advance in the Champions League," he told skysports.com. "If we beat Man City we will have six points out of six and can proceed more calmly.
"Manchester City possess a big squad but I think that Bayern are superior. We need to confirm this on the field.
"I believe that in this group the battle for second place will be hard because I bet on Bayern to be the leaders.
"For us this Champions League is special. The final is in our stadium and our challenge is to play this final."
Rafinha accepts that Bayern will have to be wary of the threat provided by players such as Sergio Aguero, who he feels has improved since joining City from Atletico Madrid.
"Kun Aguero is a star but we can stop the Argentine. Our mission is to not only stop his goals but also his assistance to the team.
"I have watched him on television and Aguero has got better since arriving in the Premier League."
Source: Team Talk
Source: Team Talk