5 Players Chelsea Should Sign That Haven't Been Rumoured This Transfer Window

Chelsea have flown out of the traps this transfer window having already made some of the biggest signings in the Premier League so far.

The Blues have focused the majority of their strengthening in the attack-minded midfield area, with Cesar Azpilicueta being their only defensive addition.

So far this season Chelsea have looked very impressive in attack, with recently signed star Eden Hazard already lighting up the Premier League with his flashes of brilliance.

But they have looked a bit shaky in defence and the centre of midfield, which could become a problem as the Premier League and Champions League campaigns kick in to full swing.

Chelsea aren't expected to make many additions on deadline day this summer and the odds of them making the most signings is as big as 20-to-1.

But Roberto Di Matteo has seen his sides' defensive frailties and may attempt to nip these issues in the bud before they become a major problem.

Add to this that Chelsea only really have one out-and-out striker in their ranks—this may be another area that requires new recruits.

Here are five players that Chelsea should look at that haven't been seen in rumour mills recently.

Demba Ba

It has been made clear that Fernando Torres is the main man for Chelsea this year, and he has repaid this faith with an impressive start to the season.

But if he was to get injured or banned, then Chelsea are very thin in the striker department and could be in some trouble.

There have been some concerns that if another striker was to come in to the club then Torres' confidence could take a knock but if he is assured that he is still Chelsea's main striker than this shouldn't be an issue.

One player who could work as cover for Torres would be Newcastle striker Demba Ba.

The 27-year-old Senegalese striker has really impressed in the Premier League and has already adapted to the style of play in England, which is an important criteria in deadline day signings.

He could also play in a formation with two strikers - should Di Matteo choose to go that way - having already struck up an impressive partnership with Papiss Cisse at Newcastle.

He has reportedly already been subject to a £7 million bid from Russian club Rubin Kazan, but Ba has apparently stated his desire to stay at Newcastle.

But this desire could just be to stay in the Premier League, so a similar bid from Chelsea could be enough to tempt Ba to Stamford Bridge.

Lassana Diarra

Why did Chelsea let this man go?

He impressed at Chelsea and has impressed all over Europe since he left Stamford Bridge.

He can play in an advanced midfield role, but he is very competent in a defensive midfield role.

But he has recently become surplus to requirements at Real Madrid with him having to fight for his place with Sami Khedira.

Diarra is still only 27-years-old and still has a few seasons left in him at top level. With his vast experience in the Premier League and Champions League, he would be an improvement to any side.

Maybe most importantly, he knows Chelsea well having spent two years at Stamford Bridge and he knows the pressure that comes with playing for big teams.

He has the pace to keep moves flowing from defence to attack, and with him not being required at the Bernabeu, he could be available in a cut-price deal.

Seydou Doumbia

This man cannot stop scoring. Despite playing for the Russian league, but his record is still very impressive.

Seydou Doumbia is a 24-year-old forward who is currently plying his trade for Russian giants, CSKA Moscow.

When a player is good in a "weaker" league, doubts always creep in about whether they can bring that form to one of the bigger European leagues.

Well these same doubts were raised about Eden Hazard and he seems to have started pretty well.

Doumbia has been the subject of interest from Arsenal and Napoli in the past, with a £15 million fee being reported as enough to lure him away from Russia.

If Chelsea could swoop for Doumbia, then they would be getting a proven goalscorer and great cover for Torres.

And perhaps a superstar in the future.

Marouane Fellaini

David Luiz has proven that big hair goes down a storm at Stamford Bridge.

And he, along with Marouane Fellaini, have proven that there are good footballers behind the big hair.

Fellaini has had an explosive start to this Premier League campaign and has already caused Manchester United and Aston Villa all sorts of problems this season.

Fellaini is a versatile midfielder and, during his time at Everton, has moved from a holding role to an attacking role.

Chelsea have reportedly shown interest in him in the past, but this seems to have died down in recent weeks.

In Felliani, Chelsea would have a holding midfielder who can actually play the game fluidly, as well as another option in attacking midfield should anybody get injured.

Cheick Tiote

The jury is still out John Obi Mikel, with some fans being impressed by him and some well not so much.

Watching Mikel, he is a player that tends to slow a move down, and with Chelsea's new look, style of play and attacking options, this may become a problem.

Michael Essien is another option in that area, but he has not been the same player since his return from injury.

One name that has been mentioned in the past is Cheick Tiote, the midfield powerhouse who currently plays for Newcastle United.

He is Essien-esque in the way he powers through midfield, and is far more composed and solid on the ball than Mikel.

He could probably be available for around £10-15 million and as he knows the Premier League well. He could fit in to the Chelsea side quicker than most new signings.