With an organised defence, vibrant midfield and a monster striker in Costa, the Blues are the team to beat.
REPORTING FROM THE UK
Hard as it is to believe, it is now over three years since Chelsea last made a serious challenge for the Premier League title and over four years since they last actually won it.
Expect that to change this season. After six years of throwing money at self-inflicted problems and one of transition, a blue power is rising once again in west London.
In the seven years since Jose Mourinho first left the club, Chelsea won a single league title and a Champions League that owed more to extraordinary human endeavour than it did exceptional quality.
The conquerors of Europe stumbled home in sixth position that season.
They have won a clutch of domestic cups of course, but the serious honours have been rather harder to come by.
There remains a sense that they have squandered the advantage they had when Roman Abramovich first pumped the club full of cash.
Now, after the short tenures of Avram Grant, Luiz Felipe Scolari, Guus Hiddink, Carlo Ancelotti, Andre Villas-Boas, Roberto Di Matteo and Rafael Benitez, Abramovich's first managerial appointment has returned and Chelsea are a far better proposition for it.
Mourinho overplayed the "little horse" theory last season, there are 88 other clubs that would love to be as "little" a horse as Chelsea, but his point that the team were not ready for the title was absolutely fair.
Too many cooks had certainly spoiled the broth at Stamford Bridge.
In Fernando Torres, Demba Ba and Samuel Eto'o, there wasn't a single striker capable of spearheading a fight for the big prizes.
The fact that Chelsea finished just four points off the title and reached the Champions League semi-finals was a testament to Mourinho's skills.
That was an unbalanced and ill-prepared squad, but he made the best of what he had available.
The addition of Diego Costa is an obvious benefit.
The Brazil-born striker is tenacious and nasty, and that's exactly what Mourinho likes.
He'll be a perfect fit, not only for the goals that he scores, but also for the way he'll dominate the final third and bring the attacking midfielders into the game in a way which was clearly beyond his predecessors.
Cesc Fabregas is one of those rare examples of a perfect signing.
His quality and mentality are beyond doubt, he knows the English league and he works hard.
Losing a legend like Frank Lampard would hurt any club, but Fabregas is a wonderful replacement.