The preliminary rounds are over, battle lines have been drawn and tonight the giants of European football resume hostilities.
Last season, Chelsea overcame a myriad of problems to finally deliver the trophy that Roman Abramovich had spent almost a decade, and hundreds of millions of pounds chasing.
Fans will hope this season's edition will be as exciting as those that came before it.
As we prepare for kickoff there are so many questions running through my head.
Is Jose Mourinho the man to finally bring home "La Decima"?
Will Man City's domestic success spur them to similar heights in Europe?
Can Chelsea, and Roberto Di Matteo repeat last season's success after a raft of big money signings?
How will Tito Vilanova adapt to life now that Barcelona has removed the word assistant from his job title?
Who will be this season's Apoel Nicosia, who emerge from nowhere to shock the big boys?
In this list I will break down the one glaring weakness that each potential contender will need to overcome to achieve the ultimate glory.
It will be no easy task emerging from a group that contains two European greats in Real Madrid and Ajax, not to mention one of the up-and-coming teams in World Football Borussia Dortmund.
While City on their day are more than a match for most teams, European football is a different kettle of fish.
Too often, City struggles when opponents stifle their fluid passing game, and struggles for a Plan B when things are going against them.
Given the money they've spent in recent years, it is shocking that they have failed to invest in a couple of decent wingers.
In Edin Dzeko they have one of the better headers of the ball in World Football, yet he seems wasted as there is no one to supply the ammunition.
He is at his best as an inverted winger, cutting in from the left onto his favoured right foot.
City is so good that Plan A will work against most teams, but they might struggle when they come face-to-face with the leading lights of the European game.
Now that United's defensive injury crisis has been put to bed, the most glaring weakness is the age-old issue in central midfield.
Don't get me wrong they have a talented bunch of players, but they seem to operate below the levels required to win in Europe.
Much depends on the injury-prone duo of Tom Cleverly and Anderson to provide the energy that compliments the playmaking abilities of Michael Carrick and Paul Scholes.
Carrick, while a key-man domestically, has often been underwhelming in Europe. At 31 it is now-or-never if he wants to make his mark in the Champions League.
As for Scholes, should United win, he would become just the third player to win the Champions League in three different decades.
The most interesting news regarding United's squad was the inclusion of Scottish workhorse Darren Fletcher.
Ever under-appreciated, it is only in his absence that fans and pundits realise just how important he is to United.
If he can overcome his unfortunate illness, United fans will hope that he can spur United on to redeem themselves for last season's horror show.
Chelsea's hot start to the season was tempered by the drubbing inflicted on them by Atletico Madrid in the European Super Cup.
Didier Drogba's departure to China left the door open for Fernando Torres to become top-dog and finally start paying off that £50 million pound investment.
Despite the array of attacking midfielders available to lay on chances, he has struggled so far to stamp his authority on the team.
No matter how good the rest of their team is, Chelsea will struggle without a focal point.
The rumoured interest in Hulk, Andre Schurrle, Edinson Cavani and Falcao came to nothing, so Torres will have at least six months to show his worth.
He will need to fight his way out of this slump, and with Eden Hazard, Juan Mata and Frank Lampard providing the ammunition, he just might.
If he does, Chelsea will be a scary proposition for any team, but I'm not holding my breath.
One of the more surprising stats of the first four weeks of the season has been that Arsenal has conceded just one goal. At the same stage last season they had conceded 10!
All this, despite the fact they have been missing a host of key men. Could it be that new Assistant Manager Steve Bould has achieved a minor miracle in his short time in the role?
I may be wrong, and will happily admit it if so, but I believe they will have issues at the back once they come face-to-face with better attacks as the season goes on.
Per Mertesacker has been imperious to start the season, and while you don't win 82 caps for Germany if you're not good, there is a reason last season was his first at a top club. He will be exposed by the top level sides Arsenal will meet in the knockout stages.
Arsenal fans will be praying that Bacary Sagna makes a swift return from injury, as Carl Jenkinson looks like an accident waiting to happen.
With a relatively easy group, Arsenal should advance without really being tested, which might go against them in the latter stages.
Nothing cuts through a squad quite as dangerously as malcontent. If it's not dealt with, it can destroy whole seasons, not to mention careers.
And something is not quite right at Real Madrid. Coming off their worst start in over 10 years, they already find themselves eight points off the pace.
Their current issues are hugely surprising as they appeared on the verge of greatness last season. They were unstoppable in Spain, and finally got the better of arch-rivals Barcelona.
Whatever the reason for the lack of harmony, Madrid will need to sort it out ASAP. Their start means they won't have the luxury of resting players before big games which will place even more pressure on their embattled stars.
Could the reason Jose Mourinho has never stayed more than three years in any job be that his influence is at its best in short bursts, and begins to wane with time?
Both he and Ronaldo will be aware that winning "La Decima" would ensure their names go down in the history books alongside the many greats who have graced the Bernabeu.
There is no questioning Carles Puyol's standing in the game. He will go down in the history books as one of the greats.
But last season he became a liability, as his lack of height and pace, left him and Barcelona exposed at the back, as exposed by Ramires in the Champions League semi-finals.
It didn't help matters that the immensely talented Gerard Pique was having his own issues. He seemed, at times, to be believing his own hype and was caught up in celebrity lifestyle. Hopefully, last season's failures will spur him back to his best. With Josep Guardiola gone, he has a clean slate to work with.
Javier Mascherano and Sergio Busquets have done a fine job when covering at the back, but that has more to do with the team's dominance of possession than their own abilities.
Barcelona will hope that one, or both, Marc Bartra and Andreu Fontas make the leap to the next level or they may fall short again.
In Arjen Robben and Franck Ribery, Bayern Munich have two genuine superstars. But when it comes to genius you sometimes have to take the good with the bad.
Both players enter the season with serious questions hanging over their heads.
Ribery is waiting to stand trial for solicitation of a minor, an offence that dates way back to 2008. The girl in question is Zahia Dehar and he is not alone in his plight, being joined by compatriot Karim Bezema.
Though Bayern Munich has vowed to stand by him, he faces a three year jail sentence if found guilty. At his age, the sentence could be a career-killer.
Whatever the outcome, the trial is bound to weigh heavily on him which may disrupt his performances on the pitch.
To compound Bayern's problem, their other star man Robben has his own issues.
Not known for being the easiest player to work with, he may cause problems should he lose his place in the team to new signing Xherdan Shaqiri.
In a country known for it ruthless efficiency, it is surprising that Bayern has placed so much responsibility on the shoulders of two enigmatic, divisive characters.
Looking through Dortmund's roster, it is easy to see why they are seen as the rising stars of the European game. The team is blessed with young talent all over the pitch.
In Neven Subotic and Mats Hummels, they have a centre-back pairing to rival all the top clubs. They are flanked by the talented overlapping fullbacks who look to get forward at every available opportunity.
The midfield is anchored by the talented Sven Bender and veteran Sebastian Kehl, who sit back and unleash the exciting duo of Mario Gotze and Marco Reus.
Their team is topped off with one of the hottest strikers in Europe right now, Robert Lewandowski.
But we all know that a team is only as good as its weakest link, and that link is goalkeeper Roman Weidenfeller.
He's no Massimo Tiabi, but is simply lacking the quality required to achieve greatness.
Given how open Dortmund attacking style of play leaves themselves open at the back, they are surely crying out for a top class keeper to be the last line of defence.
Given the depth of quality keepers available in Germany at present, it wouldn't be a huge surprise if Dortmund made a move to replace him in the near future.
There is a saying in football that says great teams are built, not bought. PSG will hope that they can prove it wrong this season.
Backed by their oil-rich Middle Eastern owners, PSG has been making huge waves in the transfer market.
After a £200 million outlay in the last two seasons, the owners will hope manager Carlo Ancelotti can mold a team that can compete in record time.
Their stuttering start to the season has shown that there are still issues that need to be ironed out as the team tries to build chemistry.
If Manchester City and Chelsea's history is anything to go by, PSG is more likely to find success at home initially, while struggling in Europe.
That said, they have signed a host of experienced stars that will ease the teething process.
They are also helped by the fact that they have drawn a relatively easy group, avoiding all the big boys and giving themselves a good shot at making the knockout stages.
For much of the last decade AC Milan has been defined by a host of star names that called the club home.
These were individuals of huge personality, that provided huge character and leadership, both on and off the pitch.
But those days are numbered as the Rossoneri have waved goodbye to Alessandro Nesta, Gennaro Gattuso, Filippo Inzaghi, Clarence Seedorf and Andrea Pirlo in the last two years.
While these men's abilities were in decline, they were no less valuable to the squad.
Their losses are expounded by the departure of superstars Thiago Silva and Zlatan Ibrahimovic. The question they face this season is if the new generation can step up to the plate.
What they lack in star-power, they will hopefully make up for in enthusiasm and endeavour.
Their team is littered with unfulfilled potential, potential that Massimiliano Allegri will be hoping he can make the most of.
Their group is all the more difficult in the wake of Zenit St. Petersburg's last-minute moves for both Hulk and Axel Witsel.
For most of last season the Antonio Conte story seemed like something you would read in Roy of the Rovers.
He was one of the most decorated and respected players in Juventus history, a hard-working player who reflected the blue-collar values of Turin.
Having served his apprenticeship at Arezzo, Bari, Atlanta and Siena, he ascended to the Juventus job at the dawn of a new, exciting era.
Their season could not have gone any better, going unbeaten in all competitions until the very last game of the season, when they lost the Coppa Italia to Napoli.
But as they marched towards immortality, Conte's name began to be mentioned in relation to match fixing.
Conte was accused, and found guilty, of involvement in the Scommessopoli match-fixing scandal and was handed a 10 month ban.
While he can still work with his players during the week, both he and his assistant Angelo Alessio will be unable to play a part in match day affairs and another key coach Cristian Stellini has resigned.
He is a huge loss to this Juventus side as he is a man of immense presence and charisma, and the players will have to learn to take more responsibility.
Teams can overcome obstacles like this but one only needs to look to the NFL, and its New Orleans Saints to see how losing a coach can hurt a team.