The 'Special One' has returned and expectation is high in west London. Jose Mourinho may have fallen out with just about the entire Real Madrid squad but he is back at a club he loves, where the fans have welcomed him with open arms, and there are still a number of players who remember his glorious first spell in charge of the club.
Mourinho has declared that he is back for the long haul but has tried to play down suggestions that he will force Roman Abromovich to delve into those incredibly deep pockets. Having won the Europa League last season and once again qualified for the Champions League there is a feeling this squad is ready to challenge for major honours again next season.
Business so far
Aside from the appointment of Mourinho it has been a busy summer when it comes to players leaving the club. Long-time servants of the club Paulo Ferreira and Florent Malouda have been released, as has Yossi Benayoun. Back-up goalkeepers Hilario and Ross Turnbull have also departed, along with young trio Amin Affane, Archange Nkumu and Aziz Deen-Conteh who were deemed to have not made the grade.
A deal is rumoured to be in place for Bayer Leverkusen forward Andre Schurrle, while Michael Essien is set to return from Real Madrid and is likely to once again play a part after playing a leading role under Mourinho in Spain.
What they need
Technical director Michael Emenalo and Mourinho will have to play nicely in order to decide who arrives at the club but it is clear a number nine is a priority. Demba Ba had a mixed time after arriving in January, while Fernando Torres struggled in the Premier League and has been linked with a move away from the club.
A back-up goalkeeper is likely to arrive after Hilario and Turnbull departed, while the highly rated Thibaut Courtois is likely to once again return to Atletico Madrid for another season long loan. With Mourinho also suggesting John Terry will no longer be first choice, and with rumours David Luiz could be sold to Barcelona, a new centre-back or two may also be high on the list of priorities.
Who could join
Take your pick from a list of strikers that includes Napoli's prolific forward Edinson Cavani, Fiorentina's much sought after Stevan Jovetic and unhappy Zenit star Hulk. German forward Schurrle is also expected to arrive at some point after meeting with Mourinho while playing in Michael Ballack's testimonial.
There have been plenty of rumours when it comes to strikers but elsewhere it is difficult to know who will seriously be targeted. Porto's French centre back Eliaquim Mangala has been mentioned, while Southampton left-back Luke Shaw is also reportedly on the club's radar. Wesley Sneijder has also talked up his relationship with Mourinho but it seems unlikely the Dutch midfielder would end up at Stamford Bridge.
Who could leave
Despite winning over supporters and the majority of the media with his performances, it seems Mourinho is not the biggest fan of David Luiz and the Brazilian could be on his way to Barcelona. Belgian youngster Kevin De Bruyne is likely to move to Germany either on-loan or as part of a deal for Schurrle, while his fellow countrymen Courtois is also likely to head back to Spain.
Torres is unlikely to convince Mourinho he deserves another chance and could well link up with Rafa Benitez once again, this time at Napoli. The former Blues boss is also said to want Ramires but Chelsea would certainly not want to lose the hard working Brazilian. Long-serving defensive midfielder Jon Obi Mikel could also be on his way out with suggestions he is already in talks with Turkish giants Galatasaray.
What the manager has said
"It was an easy decision. I met the boss, the owner and I think in five minutes after a couple of very short but pragmatic questions we decided straight away. I asked the boss 'do you want me back?' and the boss asked me 'do you want to come back?' I think in a couple of minutes the decision was made."
"I promise exactly the same things I promised in 2004, with this difference to help - which is I'm one of you."
Asked if this was a long-term project, he responded: "I hope so. When you look at the profile of the Chelsea squad I think it's what they need at this time. It's very important for this club and very important for the balance of the squad, but it's a young squad with a lot of talent and I think they need stability to reach a high point of their evolution and for their careers."