Room for improvement: 1 area of concern for each title contender

With apologies to Everton, the Premier League's top seven after two months of the campaign includes six clubs that appear poised to challenge for a title in what's shaping up as the English top flight's most competitive season.

With dozens of matches left before the transfer window opens in January, personnel changes have to come from within, forcing the Premier League's luxury sides to work with what they have.

Here's a look at the Premier League's six title contenders, and one area each side should address to make sure its title ambitions don't become pipe dreams:

Manchester City

While Manchester City boss Pep Guardiola's Christmas list is just the word "full-backs" written in crayon a hundred times, for now, the Catalan gaffer is forced to function with what he has.

All due respect to the decorated careers of Bacary Sagna, Pablo Zabaleta, and Gael Clichy, but MLS is on Line 1 and a guy from Guangzhou Evergrande is at the door with blank cheque in tow.

During Saturday's Barcelona reunion with Ronald Koeman and Everton, Guardiola worked around a dearth of full-backs with a 3-2-4-1 formation. Several steps slower than during his Arsenal tenure, Clichy was protected in a central three with John Stones and Nicolas Otamendi, while Raheem Sterling and Leroy Sane played wide in front of the defensively disciplined pairing of Fernandinho and Ilkay Gundogan.

For the time being, the 3-2-4-1 will work in certain instances, and with 72 percent possession and 19 attempts on Saturday, it should have worked against the Toffees. City supporters can thank the futile penalty attempts of Kevin De Bruyne and spot-kick misfit Sergio Aguero, along with Maarten Stekelenburg's unexpected Lev Yashin impersonation, for the less satisfactory result.

Arsenal

If Modou Barrow's marauding second-half manipulation of Nacho Monreal during Arsenal's narrow 10-man victory over Swansea City on Saturday was any indication, the Spanish full-back has lost a step.

That's not to say he's useless - on the contrary, Monreal's still one of the league's best defenders, though against pace, he's become a liability in a squad that's addressed many of its prior faults.

Solution: Kieran Gibbs. Loyal servant to the club, Gibbs has appeared as a sub in three league matches, adding defensive discipline late as the table-topping Gunners cling to one-goal advantages. With more pace than his colleague, and Arsenal invested on four fronts, perhaps Arsene Wenger would be wise employ the local boy more often.

It also wouldn't hurt to hand Hector Bellerin a break, starting with the midweek Champions League visit from Ludogorets. Short on match fitness, Carl Jenkinson was just reintroduced with an hour run-out in an Under-23 draw with Southampton on Friday, and Wenger will hope the childhood Arsenal fan is nearing a first-team return.

Tottenham

It's hard to nitpick the league's only unbeaten side, which has surrendered a scant four goals in eight matches, but that's the drill, and for Tottenham supporters, one glaring need is hard to overlook: goals.

Disregarding that 4-0 victory over a porous Stoke City at the Britannia, Mauricio Pochettino's lot has bagged just nine goals in seven tilts, including three victories over Middlesbrough, Sunderland, and Crystal Palace by one-goal margins.

Against Palace, Spurs left it close, with Victor Wanyama scoring his first for club in the 82nd minute. It was more of the same Saturday at West Brom, when Dele Alli's 89th-minute tally saved the north Londoners from embarrassment in a 1-1 stalemate.

Last season, Spurs scored three or more goals eight times. This campaign, they've done it once.

Liverpool

Through seven matches, Liverpool has conceded 10 times, failing to keep a clean sheet in any of those fixtures. While scoring doesn't appear to be an issue for Klopp's high-pressing scheme, keeping balls out of its own net does.

Even in an opening-day victory over a makeshift Arsenal side at the Emirates, Klopp's lot surrendered three times and was perilously close to ceding a fourth.

Some of that rests on a back four trying to integrate new boys Joel Matip and Ragnar Klavan, as Klopp's Gegenpressing demands centre-backs who can control the game. It failed against the Gunners, as it did a week later in defeat to Burnley.

While Jordan Henderson is not a defensive midfielder by trade, he has arguably been the club's most important player this campaign, slotted between Adam Lallana and Georginio Wijnaldum in a three-man midfield. That's all fine and well until the Reds lose possession, when a player of Fernandinho's or Mousa Dembele's ilk would go a long way towards bridging the gap. Emre Can might be that guy.

On the bright side, James Milner has been a revelation at full-back, allowing Klopp to avoid using ticking time bomb Alberto Moreno.

Chelsea

Adapt to the 3-5-2 or fail: That's the option under Antonio Conte, and part and parcel of that is determining the best-suited backline. Easier said than done.

Against Leicester City on Saturday, Conte appeared a tactical genius. Marcos Alonso and Victor Moses starred as wing-backs, while Gary Cahill and Cesar Azpilicueta sandwiched David Luiz in the back three in a one-sided victory over the drab defending champ.

While there's no firm date for the return of Kurt Zouma, the French youngster should walk into the starting XI. That would push Azpilicueta out to the right, where he's best suited. With Azpilicueta and Alonso playing as wing-backs, Zouma, Luiz, and either John Terry or Cahill would man the back three.

Manchester United

After a summer of opulent buys, the onus is on Jose Mourinho to make it all work, with an emphasis on Paul Pogba's spot in the squad. Slotted in alongside Marouane Fellaini in a two-man-deep hole, the world-record signing was largely ineffective in his first few matches for Manchester United.

It took the mercurial Portuguese gaffer a month to realise Fellaini is a pylon, opting instead for Ander Herrera - to dazzling results. The Spaniard sits deeper than Pogba, allowing the French international to forsake defensive duties and roam forward.

On the fringes of first-team football following a move two summers ago from Athletic Bilbao, Herrera is now one of the first names on Mourinho's teamsheet after catching the manager's eye as a second-half sub in the Manchester derby. With Fellaini back on the bench and Michael Carrick and Morgan Schneiderlin seemingly forgotten, Herrera is starring in the deepest role of his career, and Pogba is reaping the benefits.

If it ain't broke ...