Chelsea’s defence has been the great success of Thomas Tuchel’s reign — yet it could be set to become a weakness. 

Antonio Rudiger, Andreas Christensen, Cesar Azpilicueta and Thiago Silva are all out of contract next summer.

With Rudiger looking increasingly likely to leave on a free transfer at the end of the season, the Blues will almost certainly be forced to look for replacements.

Ahead of today’s clash with Liverpool, we assess some of the central defenders they could target.

Jules Kounde

Sevilla centre-back Jules Kounde will be high on the list of any club on the lookout for reinforcements. 

But Chelsea will be a big draw for any player and the European champions will fancy their chances of landing the Frenchman should they choose to make a bid. 

Tuchel's use of a back three means the Blues are likely to be looking at two types of central defender — one for the central position and another for the wide roles. 

Kounde could fit both, operating as a sweeper in the middle as Thiago Silva currently does, or pushing slightly forward from the right or left.

With 4.71 regains in the defensive third per 90 minutes, Kounde ranks third among all centre-backs in LaLiga — but he is also adept in possession. 

Ranking second for attempted take-ons (1.21 per 90) and third for completions (0.83) versus other LaLiga centre-backs, it is clear he is comfortable bringing the ball out of defence. 

Kounde, 23, seems like the perfect fit for Tuchel’s side.

Matthijs de Ligt

Considered one of the most highly-rated young defenders in Europe when he joined Juventus in 2019, former Ajax captain Matthijs de Ligt signed for the Bianconeri at a difficult time. 

As a result of those troubles, the Serie A side may be looking to offload some of their highest earners, with 22-year-old De Ligt still performing well enough to retain considerable value. 

A move to Chelsea appears to make sense and he would be a good option in a number of defensive roles for Tuchel's men. 

There have already been rumours linking him with a switch to Stamford Bridge and agent Mino Raiola believes his client is ready to move.

Raiola said: "We can all think of the clubs that Matthijs could go to. 

"That can be the Premier League but also Barcelona, Real Madrid or Paris Saint-Germain."

Milan Skriniar

There have been rumours that Milan Skriniar will sign a new contract with Inter Milan, but nothing has been announced yet. 

As long as this remains the case, Chelsea will be keeping an eye on the situation with the 26-year-old’s Slovakian centre-back's deal expiring in 2023. 

Romelu Lukaku recommended his former team-mate to the club upon his return last summer and Skriniar is certainly one of the highest-rated defenders in Europe. 

Boasting the third-highest passing accuracy compared to all Serie A centre-backs (92.58%), Skriniar has averaged 0.18 completed through-balls per 90 minutes, which speaks for his ability to thread eye-of-the-needle passes. 

As far as statement signings in the position go, this would certainly be one.

Benoit Badiashile

Given the potential difficulties in prising the best players from top clubs, Chelsea may have to look for less obvious targets. 

One of those could be young Monaco centre-back Benoit Badiashile.

As a left-footer, he would slot in well in Rudiger’s position on the left of the back three.

The 20-year-old will always look for a forward pass to drive his team forward, though at such a young age he may need some time to settle in the Premier League.

But only one centre-back in Ligue 1 averages more touches per 90 minutes than Badiashile (95.42) and he leads the way for attempted passes with 84.42.

Ben Godfrey

Ben Godfrey man has not really found his place at Everton, despite regular appearances since moving from Norwich in 2020. 

He has played all across the back four during his time at Goodison Park and also in midfield for the Canaries. 

But his best position may be as one of the wide centre-backs in a back three due to his combination of defensive nous and athleticism. 

This is the role Rudiger plays so well for Chelsea — and Godfrey, 23, could be an ideal replacement. 

Since the start of last season, he ranks 20th compared to all Premier League centre-backs for take-ons per 90 minutes, while he is 11th for crosses completed.

It would be a good move for the club and the player. 

Everton would be reluctant to let him go but are seeking funds for a squad rebuild of their own.