Argentina striker Aguero suffered a hamstring injury during the 5-1 win over Tottenham at the end of January and City manager Manuel Pellegrini has revealed that he will play no part in the last 16 first leg clash at the Etihad Stadium.
"He is not in the squad list. We will see if he can be fit on Saturday (at home to Stoke City), but maybe that is also difficult," Pellegrini said.
Fernandinho has also been sidelined since the resounding victory at White Hart Lane, but Pellegrini believes that the Brazil international could make a timely return for the mouth-watering encounter against the Catalan giants.
The Chilean said: "He has a chance. He is in the squad list.
"We will see tomorrow (Tuesday) who can start but he has worked without any problem."
City have scored 74 goals at home in all competitions this season and Pellegrini has no intention of taking a more cautious approach against the Spanish champions.
"For me it's very important to have that style of play and character, we are not just going to think about defending but what we can do with the ball," the 60-year-old added.
"When you play against Barcelona the most important thing is to be the same team you see here every week in the Premier League.
"I'm sure our fans will enjoy this game. I think they have enjoyed the season and it is important we continue to play this way."
Midfielder Yaya Toure knows City will have to be at their best to beat his former side, but has no doubt they have the ability to progress to the quarter-finals.
"We are focused for this game," he said. "We have to be 100 per cent against Barca, but if we want to be the best team in the world we have to win against these teams.
"We know it's going to be difficult, we have our chance first at home, we will try to do something."
