Aguero, City's top scorer this season with 19 goals in all competitions, limped out of Saturday's 6-3 victory over Arsenal and has been ruled out for at least a month by manager Manuel Pellegrini with a calf problem.
With concerns that the Argentina international could be sidelined for even longer, Dzeko - who has nine goals to his name this term after notching a double in Tuesday's Capital One Cup win over Leicester City - has vowed to step up in the 25-year-old's absence and help keep City in the Premier League title race.
"Sergio being out is very bad for the team because he has had an amazing season so far," he told the Daily Mirror. "He has been scoring a lot of goals and he is obviously a very important player for us.
"But that's life. Now we have to try to play games without him, and try to keep winning. I am a striker that has scored goals all my life and I love to do it. When I get a chance I try to do my best."