The English club is looking to improve its fortunes in Europe this season with careful additions in the latest in our series looking at the Premier League's top six sides.
The challenge now for Pellegrini and City is to compete on all fronts, with particular emphasis on becoming a genuine contender in the Champions League.
Work has begun at the Etihad Stadium to strengthen the squad and provide competition of the highest caliber in every position.
Willy Caballero is one such player who will do just that. A goalkeeper Pellegrini is extremely familiar with having worked with the Argentine during a successful spell at Malaga, the 32-year-old provides serious competition for Joe Hart and represents an upgrade on Costel Pantilimon, who has moved on to Sunderland.
MORE: Beautiful fans in Brazil | Barcelona's new bright kits | Juve's jerseys
Hart is likely to start the season as first choice but Pellegrini was quick to drop the England international during a poor run of form during 2013-14 in favor of Pantilimon. If Caballero is given the chance to impress in the Premier League, the current City No.1 might have a fight on his hands to get his place back.
Even the most reliable of City's title-winners are no longer guaranteed a starting place. Only Yaya Toure started more games than Pablo Zabaleta in the Premier League last season, but the fan favorite will find himself under pressure from Bacary Sagna this season.
In terms of quality, there is little separating Zabaleta and Sagna, who moved on a free transfer from Arsenal this summer.
Zabaleta - two years younger than 31-year-old Sagna - could find himself having an extended rest after his run to the World Cup final with Argentina, meaning the France international, who played just once in Brazil, could get the nod at the start of the season. Expect both players to be heavily involved this season.
Sagna's versatility offers Pellegrini another option at center back, but Eliaquim Mangala is finally set to join from Porto after a lengthy pursuit. The 23-year-old has passed a medical and looks likely to oust Martin Demichelis as central defensive partner to Vincent Kompany.
Competition for a starting position at left back will continue between Gael Clichy and Aleksandar Kolarov. The Serbian's days at City appeared to be numbered at times under Roberto Mancini, but the 28-year-old finished last season having started three more games than the former Arsenal man.
The signing of Fernando, also from Porto, could make City a more robust defensive unit. The Brazilian is an energetic, tough-tackling midfielder who nullifies threats and possesses the passing ability to start moves for his side.
In Europe, against the likes of Bayern Munich, Barcelona or Real Madrid, Pellegrini could deploy Fernando in tandem with Fernandinho, but at home in the Premier League, the Chilean could throw caution to the wind and play one of the Brazilian pair alongside Yaya Toure.
It has been a complicated summer for Toure, who was unhappy with the club after being sent to Abu Dhabi with the full squad on a post-season tour while his younger brother, Ibrahim, was dying in hospital.
But the former Barca man has since said he will stay at the Etihad this summer and, after playing more league games than any other City player last season, scoring 20 goals in the process, the Ivorian is again set to play a crucial role for the club.
Going forward, City is blessed with a wealth of creative, attacking talent in Toure, Samir Nasri, David Silva and Jesus Navas, but Pellegrini has indicated the club may still make another signing and another player familiar to the Chilean could be available.
Real Madrid playmaker Isco only arrived at the Bernabeu in June 2013, but after the signing of yet another attacking superstar in James Rodriguez this summer, the 22-year-old - who started just 23 La Liga and six Champions League games last season - could be on his way out.
Pellegrini has maintained an interest in Isco since departing Malaga, where the playmaker made his name under the Chilean. City may already be spoiled for choice, but Isco would only improve an already exceptional squad.
After an injury-ravaged season in which he still managed to score 17 league goals in 23 games (and just 20 starts), Sergio Aguero struggled to light up the World Cup but is expected to get the nod ahead of Edin Dzeko, who was vital to City's title victory last season, and Alvaro Negredo, who has been ruled out for two to three months with a broken metatarsal sustained in preseason.