The Premier League champions face a do-or-die clash at the Stadio Olimpico without their talismanic striker after Aguero sustained a knee injury against Everton on Saturday.
Dzeko has himself missed four games with a calf injury but he is back fit now and he is confident he can fire City to a win against Roma and help them progress to the knockout stage of Europe’s elite competition.
“I’m there when the team needs me and I’m happy to be back,” Dzeko said.
“It was a bit hard for me but now I’m back and I’ll do my best to try and score the goals and bring something good to the team.
“I always try to do my job and my job is to score goals and I will keep scoring them, I’m sure, if I (keep) healthy.”
Dzeko did admit that Aguero’s injury was a big blow to the team but he was keen to stress that the team is rounding into form and he is confident that will continue, even in the Argentine’s absence.
“It was a big blow for us,” Dzeko admitted. “You can see how many goals he scored in (the) last few games and he is our best and biggest player, with David Silva.
“Hopefully (it will not be) too many weeks but we have to deal with it. We have won five in a row.
“There is better confidence, better atmosphere in the team when you’re winning the games and I think we’re coming back to our normal performances. Hopefully we can be even better in the next week.”
The permutations for City to qualify are not straightforward, as they head into the final round of Group E fixtures level on five points with Roma and CSKA Moscow in the race for second place.
They need to win and hope CSKA do not beat Bayern, or at least claim a score draw if CSKA lose.
Dzeko is expecting a tremendous atmosphere in Rome and admits he cannot wait to take the pitch.
“I think the atmosphere will be amazing and that’s what football’s about, and those are the kind of games we want to play,” he said.