The two clubs had a very different transfer summer which could impact the outcome of the game..
The start of the season for Manchester City and Chelsea has been a bit of a roller coaster. Despite the hiccups against teams like Cardiff City and FC Basel, both sides still stand strong in the league and are comfortable in their respective Champions League groups.
With Jose Mourinho back at the helm, Chelsea are automatically considered favourites to land the league title. A squad consisting of a plethora of attacking talents, the experience of the old guards and the meticulous planning and tactics of Jose Mourinho were enough to tip the odds in favour of the Blues.
Back when Mourinho arrived at Stamford Bridge for the first time in 2004, much of his success was down to Roman Abramovich's millions. The Portuguese's tactical awareness complemented the cash at his disposal and led to the creation of one of the finest Premier League sides. Not many clubs could match their level of spending, it was something English football had never seen before. A unique concept.
Mourinho left the club a couple of years later and thus started a similar resurgence at another Premier League side - Manchester City.
Backed by Thaksin Shinawatra from 2007, City transformed from a mere mid-table club to one that could challenge the 'top 4' of English football. Thaksin's City under the guidance of Sven Goran-Erikson saw some much needed cash injected into the squad and the likes of Elano and Martin Petrov began to turn the club's fortunes around.
Sheikh Mansour continued where Shinawatra had left off and the signing of Robinho from under Chelsea's noses turned out to be the turning point for the two clubs and thus a rivalry was forged. Mansour not only spent money on the recruitement of new players but also on the club's facilities and staff.
So, when Jose Mourinho made his return to Chelsea this season he saw a new financial power leading the Premier League summit.
Mourinho is no stranger to this Manchester City side though. Last season's Champions League group games is clear evidence of what the Portuguese could be up against this Sunday. The only difference is that Manchester City are even stronger and his Chelsea side lack the cohesion of Real Madrid last season.
Speaking of City's new signings this season, the former Porto boss was impressed with what Pellegrini had at his disposal and why there is a difference in philosophy of the two sides.
“If you see their age, their maturity, they are in the perfect moment of their career to go to England, no need for adaptation, no need of work to learn the project. They are players at the top of their careers, experienced but still young, so I think they've bought very, very well".
There is a difference in transfer philosophy at the moment between Chelsea and City. Chelsea with their new signings of Marko Van Ginkel, Andre Schurrle and Willian are looking to invest more into their future, City on the other hand are spending more on finished products with the experienced Jesus Navas and Fernandinho.
But despite the contrasting nature of the two clubs one would have expected Chelsea to find answers to their major weaknesses from the past few seasons. City did that, Chelsea it seems have left it for another season.
The Blues' frailty in the central midfield and the striking department is no secret. Rafa Benitez tried to rectify the midfield with the introduction of David Luiz in that role but Mourinho sees the Brazilian as a center-back rather than the anchorman in midfield. Frank Lampard who signed a new 1-year contract at the end of last season is still being trusted by Mourinho as he looks to convert him into a deep lying-playmaker alongside Ramires, which at this point does not look to be going the right way for Chelsea.
Michael Essien and John Obi Mikel provide the other options in midfield but it seems like the Portuguese is content with his first-choice pairing. New signing Marko Van Ginkel, last season's Eredivise young player of the year will miss the rest of the season due to injury.
Compare this to Pellegrini's midfield and on paper there is only one winner. Obviously, games aren't won on paper but City's midfield is something Chelsea would love to have at this point. Yaya Toure, who already showed his credentials in the league, has been ably supported by new signing Fernandinho. The Brazilian who tormented Chelsea last season in the Champions League group stages has settled well to life at his new club and it seems like he perfectly replaced Gareth Barry in the double pivot.
The biggest contrast in the two sides are the striker's. Manchester City have the wealth of in-form Sergio Aguero, Edin Dzeko and new signings Stevan Jovetic and Alvaro Negredo. Although Jovetic is yet to be given a proper run in the side, Negredo's excellent form alongside Aguero has become the envy of the league.
Aguero and Negredo have scored a total of 16 goals in all competitions this season. The Spaniard has scored four goals this season and has been excellent when coming on as a substitute, scoring thrice from the bench.
Chelsea's front three of Fernando Torres, Demba Ba and Samuel Eto'o have managed a mere three goals in all competitions with just one goal in the league that came last weekend.
Chelsea's striking issues are there for all to see. Fernando Torres will never regain his lost form and even though the Spaniard is looking a bit confident under Jose Mourinho, Chelsea's need for a new and prolific striker is something they should have answered early on in the season.
Chelsea's relentless pursuit of Wayne Rooney throughout the summer ended in vain. Manchester United declared that the forward was not for sale, which left Chelsea with no option other than to move for the aging Eto'o. Despite his excellent past, the Cameroon international was only seen by many as an entr'acte in the development of Romelu Lukaku.
The former Barcelona striker is still finding his feet at Chelsea and even though he played a major role in the club's 4-1 win over Cardiff last week, the prospect of him scoring 20-plus goals this season still looks like a long shot.
Chelsea's two major acquisitions Andre Schurrle and Willian only added to their wealth of creative midfield talents at their disposal. Although Schurrle's early signing made sense considering it only added more depth in that department with the departure of Marko Marin, Victor Moses and Florent Malouda, the decision to spend on Willian despite his brilliance looked more of a luxury rather than need.
The Brazilian has only started one league game this season and seems to be behind Juan Mata in the pecking order. Andre Schurrle has had a comparitively decent start to his Chelsea career. The German has overthrown Mata from the starting line-up on numerous ocassions and it seems he has established himself in Mourinho's trio of attacking midfielders.
The Blues needed to get their transfer priorities right this season which they failed too and even though they landed two major attacking threats in Willian and Schurrle their requirements were not met. City on the other hand added players on all fronts. Jesus Navas added the much needed spark in the wings which was missing last season and Negredo has ably replaced Carlos Tevez.
In Fernandinho the club looks to have finally found an able partner for Yaya Toure. Despite missing out on their two major targets, Radamel Falcao and Isco, Pellegrini's decision to land Negredo and Jovetic has somewhat made amends for their earlier loss.
Yes, games aren't won on paper but your on-field performances, but City's successful transfer window has already given them an advantage as we enter the first 'El-Cashico' of the season.
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