Every great team in history has had a "spine". These are players that determine how consistent their team is. The rest of the team rely on them to perform every week and carry them when the going gets tough.
From Cafu, Roberto Carlos, Ronaldinho and Ronaldo for Brazil in 2002, to Casillas, Puyol, Xavi and Iniesta for Spain in 2010 this has been evident on the international stage as well as in club football.
The best examples of a "spine" in club football are the successful Barcelona and Bayern teams of recent years. Each of these teams had a number of consistent performers who doubled as team leaders and motivators.
However, there is one "spine" that has outlived the rest and became the most consistent quartet in the Premier League for a decade. Even after their creator, Jose Mourinho, left Stamford Bridge in 2007 goalkeeper Petr Cech, captain John Terry, midfield goal machine Frank Lampard and the powerful Didier Drogba carried Chelsea to League, Cup and European success.
Mourinho built his team around these players and made them great. Their passion and willingness to put their body on the line for the result became infectious and helped younger and less experienced players.
The effectiveness of the quartet was never more evident than their Champions League campaign in 2012. After Andre Villas-Boas' firing, Roberto Di Matteo took over and put his faith in those four players. This worked a charm and come May they were Champions League winners.
Now Mourinho is back in SW6 and it is highly anticipated that he will forge a new "spine". Three of the four remain but even though Cech is still considered one of the best 'keepers in the world, he is prone to mistakes such as the one to allow West Brom score a second on Saturday.
Terry has had something of a resurgence since the return of The Special One and is proving to be Chelsea's most consistent performer until now. However, even the 'Captain, Leader, Legend' will not be able to carry on forever.
Lampard is noticeably getting slower and he is finding it hard to adapt to a new defensive position this late in his career. He has played almost every game this season but the days where he could play three games a week are gone.
Although still a mainstay in the team and surely a leader in the changing room and an inspiration for younger players, his form is dwindling and at this level in football, it is unrealistic to assume that he can carry on for much longer.
It is expected that these players will be moved on and replaced by new players in the next couple of years.
Chelsea already have a ready-made replacement for Cech in Thibaut Courtois. Courtois has been in excellent form and has proven his ability on countless occasions during his three year loan spell at Atletico Madrid.
He is expected to come back next year but has stated that he is not going to return to sit on the bench and after Cech recently signed a new long term deal which ties him to Chelsea until 2016. With neither player willing to accept a bit-part role, it will be tough for Mourinho to juggle the two players' wishes and ambitions. In the long run it would make more sense to give Courtois a starting berth and hope Cech can mentor him for at least a year before moving on.
Many think that David Luiz is already a leading player in the Chelsea changing room and has a shot at being future captain. Whilst these assumptions are far-fetched, it is without a doubt that Luiz is quality.
He has proven it and will continue to prove it in the future. The main criticism that has been aimed at the Brazilian defender is that his lack of concentration costs his team dearly like against Cardiff this season.
However, if there is anyone who can man-manage Luiz and usher him to greatness it is Mourinho. Luiz could be an ideal long-term replacement for Terry in the heart of the Blues' defence. Both are strong, are dominant in the air, have the ability to score goals and both can play out from the back.
Oscar has been playing consistently well this year and has become a favourite for the number 10 role behind the striker - even forcing twice player of the year Juan Mata out of the team. He works hard off the ball and has a Brazilian quality on it.
He is a goal-scoring midfielder who is reliable and can produce unexpected magic when called upon. Already a favourite of the reinstalled Chelsea managed, one does not need a great deal of imagination to see that he will be a mainstay in the team for years to come. His energy, skill and goal-scoring prowess will serve as the perfect replacement for Lampard's skill set.
Chelsea have been searching for Drogba's replacement ever since his memorable winning penalty in Munich. Fernando Torres was given the chance to step out of the great man's shadow but has failed to do so yet.
With Demba Ba proving to be an able back-up but no more than that and Eto'o considered a short-term option, there is only one more striker in the Chelsea fold who could step up to the plate.
Ironically, Romelu Lukaku has been dubbed the 'New Didier Drogba' and his goal-scoring exploits for West Brom and Everton in the last two years as well as his powerful playing style tell us why.
He is strong and bullies defenders to the point where they must feel it is worth giving a goal just for a few minutes rest. He couples this with a desire to win and an eye for scoring great goals with either foot.
Considering he is only 20-years-old, it seems like he has the whole world at his feet and surely he must realise that he has a great opportunity to become the number one striker in one of the top clubs in Europe.
He is a Chelsea fan and his heart is firmly set on becoming a Chelsea legend. Taking the above points into consideration, it seems that the only man who can take over from Drogba is Lukaku and he will be hoping to emulate and better the Ivorian's achievements in London.
If Mourinho plays his cards right he could have a new "spine" in a couple of years and who says the new quartet cannot emulate the old one given time? Courtois, Luiz, Oscar and Lukaku are young, motivated and determined to become legends.
Every Chelsea fan worldwide will be hoping for their continued success and development and if this happens we may yet experience the best "spine" yet.
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