Dzeko, who scored in City's 5-0 rout of Newcastle United on Saturday, was set to start up front alongside Sergio Aguero, with Fernando and James Milner replacing Fernandinho and the banned Yaya Toure in midfield.
Pellegrini also made two changes in defence, with Martin Demichelis -- sent off against Barcelona last season -- and Gael Clichy coming into the team in place of Eliaquim Mangala and Aleksandar Kolarov.
For Barcelona, cup goalkeeper Marc-Andre ter Stegen was drafted into the team to replace Claudio Bravo, while Andres Iniesta was preferred to Xavi in midfield.
In total Barcelona coach Luis Enrique made three changes to the side beaten 1-0 by Malaga on Saturday, with Javier Mascherano and Ivan Rakitic replacing Jeremy Mathieu and Rafinha.
Barcelona beat City 4-1 on aggregate when the teams met at this stage of last season's competition and are bidding to reach the quarter-finals for the eighth straight season, while City have never made it to the last eight.
Starting line-ups in the Champions League last 16 first-leg match between Manchester City and Barcelona at the Etihad Stadium on Tuesday (1945 GMT kick-off):
Manchester City (4-4-2)
Joe Hart; Pablo Zabaleta, Vincent Kompany (capt), Martin Demichelis, Gael Clichy; Samir Nasri, Fernando, James Milner, David Silva; Edin Dzeko, Sergio Aguero
Coach: Manuel Pellegrini (CHI)
Barcelona (4-3-3)
Marc-Andre ter Stegen; Dani Alves, Javier Mascherano, Gerard Pique, Jordi Alba; Ivan Rakitic, Sergio Busquets, Andres Iniesta (capt); Lionel Messi, Luis Suarez, Neymar
Coach: Luis Enrique (ESP)
Referee: Felix Brych (GER)
Source : AFP
Source: AFP