Biggest Issues Facing Chelsea in Final Month of 2015 Transfer Window

Jose Mourinho isn't happy, and he shouldn't be.

In his column for the Daily Mail, Martin Samuel claims Chelsea have gone backwards with their lack of activity in the transfer market, leaving Mourinho frustrated with the squad at his disposal.

It's not something new. It's been the theme of the summer where Chelsea are concerned.

While all those clubs around them have made significant signings, only Asmir Begovic and Radamel Falcao have arrived in west London.

All the while, Didier Drogba, Petr Cech and Filipe Luis have since departed. In terms of numbers, Chelsea are actually weaker.

We're just one game into the new season, but after this weekend's 2-2 draw with Swansea City, it's clear all isn't well with the Premier League champions.

Chelsea seem to have lost momentum—the same momentum that saw them remain undefeated in all competitions until early December last season.

That was a run of 22 games and included an impressive 17 victories in the process.

Chelsea appeared unstoppable. The talk was of them emulating Arsenal's Invincibles of 2004, perhaps even sweeping the board in England and Europe.

Since that time, things have caught up with them, however.

A reliance on a core group of players saw Chelsea stumble over the line in the Premier League. It was the good work pre-Christmas that ensured they would eventually be champions.

As for their assault on Europe, it ended early on the back of a disappointing away-goals defeat to Paris Saint-Germain in a game that outlined the deficiencies in Mourinho's squad.

Matt Dunham/Associated Press

Even with a man less, PSG were able to bully Chelsea out of the decisive second leg at Stamford Bridge.

We expected Chelsea would address those issues, but they haven't. Now, with just three weeks remaining in the summer window, they need to rush them through.

If they don't, they risk oblivion. We could be looking at a repeat of 2013/14 all over again when Chelsea were also-rans, getting close to glory but not close enough.

Chelsea's failure to sign a striker of significant quality hindered them throughout Mourinho's first campaign back as manager.

A summer-long pursuit of Wayne Rooney ended in failure, and without a back-up plan, the emergency signing of Samuel Eto'o wasn't enough.

It was remedied last year when Diego Costa arrived—his goals being the catalyst in Chelsea's title triumph.

Now Mourinho must address his problems in defence and midfield.

Before August is out, Chelsea must add two defenders and at least one more attacking midfielder of significant quality to their squad.

We saw against Swansea how a lack of depth beyond the first XI can hurt this Chelsea team.

Tim Ireland/Associated Press

To a man, Chelsea's starting lineup is one of the strongest in Europe, let alone England. There are few who can match it.

When things begin to go wrong and they need a reaction, Chelsea don't have much.

When Swansea harassed and tormented Chelsea at Stamford Bridge, Mourinho looked to his bench and couldn't offer much by way of change.

Branislav Ivanovic was on the ropes, but without a spare right-back, he was forced to continue suffering at the hands of Jefferson Montero.

It was horrible at times, as the Ecuadorian punished him, skipping past Ivanovic like a training-ground dummy to deliver cross after cross into the danger area.

Cesar Azpilicueta may have been better qualified to combat Montero's threat, with his pace a strong asset. He's Chelsea's left-back, though, so without a replacement elsewhere, Mourinho was powerless.

It can sometimes be a knee-jerk reaction to suddenly claim the loss of a player is significant when he's not around anymore.

Frank Augstein/Associated Press

An example being that there were few complaints when Luis was sold back to Atletico Madrid, yet plenty were calling for a player of his ilk on Saturday.

It's not because Luis was particularly exceptional at Chelsea. It's more to do with the fact he hasn't been replaced.

Outside of Kurt Zouma, Chelsea don't have a back-up defender anywhere in their current squad. Any back-ups are either too young to be considered right now or have moved out on loan.

It's naive in the extreme to consider Chelsea getting through the season with just five defenders. With Champions League, Capital One Cup and FA Cup duties to consider, along with the Premier League, they'll be as stale as the Christmas turkey come New Year.

The defensive strength of this Chelsea team is everything to Mourinho. It's the core fundamental he instills everywhere he travels, yet there's a risk it's going to be lacking this season simply because he can't rotate.

It's a similar case in attacking midfield where Chelsea have too much of a good thing.

Mourinho's attackers are one and the same. Eden Hazard is more direct than Oscar and Willian, but all three can be guilty of dallying too often.

The same can be said for Cesc Fabregas, who offers something very similar to his teammates.

Chelsea need to find a balance in attack. They desperately need a wide player, someone who can be direct when attacking defences and stretch teams.

Alastair Grant/Associated Press

Playing on the counter-attack, it's vital to put the opposition on the back foot, to turn them.

Oh, they do have Juan Cuadrado for that, but let's not go there. We'll save that debate for another time.

Against Swansea, even when it was 11 vs. 11, the visitors found it a simple task to contain Chelsea. There were moments they looked exposed, but Chelsea didn't test Lukasz Fabianski enough.

In isolation, we can point to it being just one game, that Chelsea aren't fully fit heading into the new campaign and will get sharper as the season progresses.

That sounds good in theory, yet the recent past tells us it's not the case. The problems Chelsea faced against Swansea are the same problems that haunted them from March until May this year.

Back then they had a points cushion to protect them. Right now their biggest protection against failure in 2015/16 is the remaining weeks of the transfer window, where they need to be decisive.

Garry Hayes is Bleacher Report's lead Chelsea correspondent. All quotes were obtained firsthand unless otherwise noted. Follow him on Twitter @garryhayes