Chelsea: Five Reasons Why Antonio Conte Faces Impossible Task to Retain Premier League Title

Chelsea scaled the mountain last season to win the Premier League under new coach Antonio Conte.

That most difficult of achievements may have been the easy part.

Chelsea owner Roman Abramovich is a notoriously demanding man and he will want Conte to follow up on that success with another title.

Here are five reasons why Chelsea will struggle to meet those lofty expectations.

Diego Costa's impending departure

Losing Costa will mean Chelsea loses goals but perhaps more importantly snarl on the pitch. Costa couldn't always control his emotions but he was a figure that intimidated opposition defenses.

If Costa leaves for Atletico Madrid—initially on loan, as Atletico has a transfer ban—Chelsea will be left with a giant hole up front.

It's also the manner of Costa's departure that should worry Chelsea supporters. It has been drawn out and acrimonious, with leaked text messages that could potentially destabilize Chelsea's dressing room that pulled together so tightly last season.

Torpidity in the transfer market

Jose Mourinho has already moved to address several of the shortcomings with Manchester United's squad. At Manchester City, Pep Guardiola has been spending money like it's going out of fashion. At Liverpool, Jurgen Klopp is about to make a statement by capturing Mohamed Salah from A.S. Roma.

At Chelsea, the Premier League champion? There has been one transaction conducted so far, with Alex Kiwomya moving to Doncaster Rovers on a free transfer.

It's hardly time to panic given we are not even into July, but it's never good to stand still and at the moment it feels like Chelsea's rivals have stolen several paces on it.

Second-season syndrome for Conte

Last year Conte had the element of surprise on his side when he switched Chelsea to a 3-4-3 formation in the autumn.

That change carried Chelsea unstoppably to the Premier League title. But now opposition coaches have had almost a full season and a summer to work out Conte's tactics.

Can the Chelsea coach adapt? His team's success next season may depend on whether he can.

John Terry's missing influence

Terry has been a hugely divisive figure in his career but there is no doubt that his influence within a dressing room is mighty.

The former Chelsea captain appeared only sporadically last season but just having Terry as a sponge from which to soak up knowledge helps any young defender.

With Terry now gone Chelsea has to find another leader with as loud a voice and that won't be easy. Otherwise, when the team inevitably hits a sticky patch during the season there will be no one to turn the situation around.

N'Golo Kante dropping off

Chelsea's midfield general has enjoyed two all-worldly seasons, first with Leicester City and then Chelsea.

France international Kante has come from obscurity at Caen to become one of the world's very best midfielders.

But it's ridiculous to expect Kante to keep performing at that level every season. At some point, he's going to suffer an injury and drop off in form.

That's when Chelsea will face its biggest test. Who will be willing, or able, to step up to the 26-year-old's level?