Lot riding on Chelsea striker Diego Costa this EPL season

Manchester City left it to the final day of the season to clinch their titles seeing off their crosstown rivals in 201112 and Liverpool two seasons later Sir Alex Ferguson and United cantered home in his final campaign in charge as did Jose Mourinho last season after the much publicised return to Stamford Bridge nearly two years earlierDiego Costa PicGetty ImagesOnce again vast sums have been staked in the transfer market as sides look to challenge Chelseas supremacy The key player however isnt a new arrival but an individual that moved to West London over a year ago When his hamstrings are in fine fettle Diego Costa is a defenders nightmare an oldstyle bruiser of a centre forward with a delicate touch and a cynical edge to his gameTill he got injured last season Chelsea were going along like a locomotive After his hamstring gave way their defensive qualities came to the fore with Nemanja Matic especially impressive in his holdingmidfielder role If Costa can stay fit for most of the season Chelsea will win the title But if hes a fitful starter and there are worrying signs that the hamstring problem is a recurring one the two Manchester clubs and Arsenal will fancy their chancesRemy is no CostaLoic Remy is no Costa and if what we saw during the Community Shield was any indication Radamel Falcao will never again be the forward he was before that awful knee injury Falcao such a letdown on loan at United last season moved as though wearing cement boots with the bursts of acceleration that once made him so feared nowhere to be seen Longtime Chelsea supporters will also worry about the impact of one of their summer salesFor a decade Petr Cech was the bedrock of one of the most imposing defences on the continent The arrival of Thibault Courtois so influential in Atletico Madrids run to the La Liga title and Champions League final in 201314 pushed him to the substitutes bench and prompted the eventual move across town to ArsenalEver since Jens Lehmanns form started to slip Arsenal have lacked a truly imposing keeper By recruiting Cech Arsene Wenger has found the biggest missing piece in his team jigsaw If Alexis Sanchez stays fit and reprises his form of last season Arsenal will challenge till the end Doubts remain over the heart of the defence but they have creativity aplenty and the bank balance to splurge on someone like Karim Benzema if Real do decide to sell him Despite his purple patches Olivier Giroud is not really the quality of striker you need to win the titleUniteds strategyUnited have sold Robin van Persie opted not to retain Falcao and also made clear that Javier Hernandez has no future at Old Trafford Theyve been linked with Bayerns Thomas Muller all summer but it would be a shock if Pep Guardiola sanctioned that saleThe one German addition to Louis van Gaals squad is an intriguing one When fully fit Bastian Schweinsteiger is the boss of midfield players a commanding physical presence with the eye for the killer pass and a nose for goal The problem is that he has rarely been fit the past few seasons a fact that Guardiola reiterated after sanctioning his saleInstead it could be Morgan Schneiderlin that proves to be van Gaals most astute midfield signing A star of Southamptons recent renaissance he offers the presence that Uniteds midfield have lacked since the failure to adequately replace Roy Keane all those years ago Of all of Fergusons mistakes few were as awful as the failure to keep Paul Pogba happy at Old Trafford After going to Juventus where he got the game time denied him at United Pogba has become the worlds most coveted young midfielderAcross town Manuel Pellegrini has run out of time Raheem Sterling has arrived from Liverpool but theres once again the sense that Citys campaign will depend on Sergio Agueros fitness With rumours rife that the owners will pursue Guardiola next season Pellegrini will need his old stalwarts most notably David Silva and Yaya Toure to shineLiverpools spendingLiverpool who have bought astutely this summer mdash if he gets the right service Christian Benteke will rival Aguero and Costa for scoring honours mdash but both they and Tottenham lack the depth to sustain a title challenge As for rank outsiders likely to challenge for a European place look no further than Alan Pardews Crystal Palace Promoted Bournemouth could also surprise a few people under Eddie Howes stewardshipDileep Premachandran is Wisden Indias editorinchief