Whenever Jose Mourinho takes over at a club, the changes are normally evident within the first few months.
To some degree that's been the case with Chelsea, with the likes of David Luiz and Juan Mata missing game-time, and Samuel Eto'o and Willian being bought in.
However come January Mourinho will know he still has work to do if he wants to maintain Chelsea's credentials as title-winning contenders.
There's been a number of transfer rumours concerning the Blues and potential targets, and you can bet that the Special One will use the winter transfer window to do some tinkering.
We take a look at a potential Chelsea XI following January, if Mourinho can get it right...
GK: Petr Cech
The long-serving Czech 'keeper has somewhat recaptured his form of old this season, and will undoubtedly hold onto Chelsea's No.1 jersey until at least the end of the season. Cech provides experience and pedigree in the biggest competitions, and providing he isn't injured, will retain his place.
RB: Branislav Ivanovic
The steadfast full-back is an important element in Chelsea's back line, and since he has so far faced minimal competition from Cesar Azpilicueta, he's a surefire favourite to hold down the right-back spot for the time-being. Offering a solid presence at the back, and good going forward, Ivanovic has developed into a reliable member of the team.
CB: John Terry
The Chelsea captain is probably in his last full season as a regular starter, but has been given a new lease of life under Jose Mourinho. Not as quick nor astute as he once was, but definitely no pushover, Terry guarantees calm and assurance at the back, and is an ideal mentor for any young defenders in the squad- namely the potentially incoming Eliaquim Mangala.
CB: Gary Cahill
The England international has hit his prime and can lay claim to being one of the best centre-backs in the country on his day. His partnership with Terry has blossomed and, now that he has a couple of season's under his belt playing for a big team, he looks more comfortable in the crunch matches.
LB: Ashley Cole
Another player who is close to calling time on his career, Cole remains Chelsea's first-choice left-back, and is still good enough to handle all but the very trickiest of wingers. The ex-Arsenal man is still one of the best full-backs in the league, and Mourinho won't be thinking about replacing him until at least the summer.
The Brazilian starlet has been in an exceptional vein of form this year, and it doesn't look like stopping anytime soon.
Oscar struggled with the physicality of the division upon his arrival to the Premier League, but has now settled in with aplomb. If his current form continues then there's no reason why he can't be aiming for personal accolades as well as team trophies come the end of the campaign.
CM: Juan Mata
It's surely only a matter of time before Mourinho realises what he has in Mata. The Spain international doesn't fit the bill for the Special One by way of being small and slight, but he is a genius when on the ball and can be relied upon to conjure something from nothing.
CM: Xabi Alonso
The playmaker is said to be mulling over a potential move to Chelsea, and Mourinho wants him to return to the Premier League. Alonso has proven himself in the Premier League already and, considering the fact he would be arriving on a free, is a no brainer.
LM: Eden Hazard
The Belgian sensation has ran rampant since his arrival at Stamford Bridge, and is unplayable on his day. Unless he suffers some horrific injury or for some reason forgets how to play football he will continue to be a major player in Chelsea's drive for success.
CF: Fernando Torres
Under the watchful eye of Mourinho the Spain international seems to have recovered at least some of his devastating form of old.
Torres may now be 29, but that doesn't mean he hasn't still got time to return to the days when he was scoring 20+ a season with minimal effort. A few more goals will help his confidence, but it looks as though he will get the nod over Samuel Eto'o and Demba Ba when it comes down to the big games.
CF: Mario Balotelli
A dubious inclusion, but one made all the more possible by recent revelations linking the ex-City nut to Stamford Bridge. Balotelli is said to be edging close to the exit door at the San Siro, and Mourinho is rumoured to want a reunion.
The Milan forward has the potential to be brilliant when he puts his mind to the task, and is a proven goalscorer in the Premier League.