The Russian side take on City behind closed doors in the Champions League on Tuesday as punishment for the racist behaviour of their fans.
After losing their opening two games against Roma and Bayern Munich, it is a game CSKA need to win to have serious hopes of qualification from Group E.
Musa is confident CSKA can do that as they face a City side that have also made a disappointing start in the competition.
Asked about City, Musa said: "As you can see, they are very weak this year
We are going to use that advantage against them.
"In a couple of games they haven't been that good
They are very weak in the defence, so we are going to do our best to work against that.
"I think we are going to have a great opportunity because of the quality of the players we have
I think Tuesday is going to be a very good game for us.
"We are going to do our best to win because this is the last opportunity that we have."
The game will be played in an odd atmosphere at the Khmiki Arena with supporters barred from the stadium.
CSKA have been punished by European governing body UEFA over crowd racism incidents three times in the last year.
The first of those offences came when City visited in the same competition a year ago and fans directed monkey chants at Yaya Toure.
Musa, speaking at CSKA's pre-match press conference, said: "We are going to miss the fans
It is very difficult for us to play without our fans."
Asked if the situation was unfair, Nigeria international Musa said: "Yes, it is unfair."
CSKA coach Leonid Slutsky was unwilling to enter the debate about racism.
The Russian club must play their next three home European games behind closed doors and are also banned from selling tickets for the return match against City at the Etihad Stadium.
Slutsky said: "Definitely the absence of the audience will affect our game and of course we need our supporters, but it is really hard for me to answer the question because I am a head coach, and to answer this question I need much more detailed information concerning this affair
I am not able to answer this question because I am a sports professional."
CSKA go into the game in good heart after beating Kuban Krasnodar 6-0 at the weekend.
But Slutsky was more cautious than Musa when asked about City's qualities.
He said: "Let's say, frankly, Manchester City have always been a favourite, not only for the group but the whole Champions League.
"Manchester City are one of the best teams in Europe
They are champions of England and have top football players, a minimum value of player is 30million euros.
"Our task is to do our best to resist this qualified opponent."
CSKA have fitness doubts over defender Mario Fernandes and striker Seydou Doumbia.
Conditions for the match were set to be cold with lows of minus five degrees forecast for Tuesday night
There was also light snowfall in Moscow on Sunday night.
Source : PA
Source: PA