Does Cahill now belong in Chelsea's strongest line-up? 

After the opening day shock defeat at home to Burnley, Chelsea have managed to get their season back on track with a string of impressive performances. The hammering of Stoke at the Bet365 Stadium was a statement of intent from Antonio Conte's men and also their leading marksmen Alvaro Morata.

One of the biggest talking points from that game, however, was the exclusion of club captain Gary Cahill from the starting eleven.

The opening day sending off to Gary Cahill after just fourteen minutes with a dangerous challenge on Steven Defour, was just another slight indication to some that Antonio Conte ought to be chasing a top-class centre-back to replace the current England international at the heart of his three-man defence.

Over the years, Cahill has split opinion among both Chelsea supporters and fans of the game. Taking the role at the heart of the Chelsea defence seemed like such a step up for the man who signed for Chelsea from Bolton.

His success for Chelsea speaks for itself, earning success in both domestic cups, both the Champions League and the Europa League and lifting the Premier League trophy last season. However, the second half of last season and the start of this season has seen the centre defender look far away from his best.

The defeat to Burnley and the sending off of Cahill has raised some question marks on his position

For much of the two summers that manager Antonio Conte has now had at Stamford Bridge, he has been looking for central defenders, after failing last summer with known bids for both John Stones and Leonardo Bonucci and later landing David Luiz.

This summer again, the Bonucci links resurfaced and the club was mentioned as a possible destination for Southampton's wantaway defender Virgil Van Dijk. Instead, the club landed the highly sought after Antonio Rudiger from Roma.

The problem that Cahill has now in this Chelsea team is that he is quickly falling down the pecking order after the impressive start Rudiger has made to life at Chelsea and the highly anticipated emergence of Andreas Christensen who has slotted into the three at the back system very well.

With the amount of games Chelsea will face this season with the return of Champions League football, Cahill will get a lot of game time still, but does he really get into the strongest Chelsea eleven, on ability?

The answer will have to be a no.

Bonucci joined AC Milan, after the links he had with Chelsea

Whenever Chelsea do look vulnerable defensively, it does seem down the left side of their defence where Cahill operates. Ideally, Cahill would prefer to play as the central defender but his positional play is not at the same level as David Luiz and his distribution from the back would not be as efficient as that of the invaluable Brazilian.

Cesar Azpilicueta is perhaps the best defender Chelsea have at their disposal and among the best in the entirety of the Premier League. So, the place at left centre back is the position that causes the most dispute when deciding the strongest line-up.

With the departure of club captain John Terry during the summer, the natural successor looked to be Gary Cahill with the experience he brings to the team and a level of leadership.

However, this Chelsea team is blessed with leaders - Fabregas, Luiz, Azpilicueta and Courtois to name a few. After the opening games of the season, the England man needs to up his game to command a starting position within the team.

At 31-years-old, Cahill should still have a good few years ahead of him, but he looks a yard of pace short from where he was at previously. His positional sense to cover spaces on the outside is poor, and wasn't particularly great last season either.

There just always looks like there's a mistake with the player now - a trait that Antonio Conte, as a manager, does not like in his defenders.

German international defender Antonio Rudiger compliments both David Luiz and Azpilicueta very well, his ability in the air is commanding, his positional sense at left centre back allows him to defend on both the inside and the outside comfortably, and he can mark forwards out of games.

When Chelsea signed Rudiger for the estimated value of 34 million it looked like he could potentially be more of a squad player with the continued links to other central defenders, however after the start he has made at Stamford Bridge, he should be the man to be alongside Luiz and Azpilicueta.

Rudiger was in fine form against Tottenham in the 2-1 victory at Wembley

Andrea Cristensen is the other defender who is competing for a place in the Chelsea back three. His previous two campaigns in the Bundesliga have served the young Danish international very well. In his first season, he even won the player of the season for Borussia Monchengladbach.

Now, at the age of twenty-one, Christensen has already showed, in his seven appearances this season, why he is touted as being among the best central defenders in Europe. Ideally he would play at the right side of the back three, but he has played in the left side role and looks as comfortable there as he does on the right.

Chelsea fans were excited to see Christensen getting a chance this season and Conte is certainly doing that, showing his faith in Dane. This season could prove a big season for the Chelsea youth, with a few players threatening to break through.

Christensen, though, promises to be the one who is most effective. The maturity he has in his game right now shows just how good he could potentially be. He reads the game well on the front and back foot, he's effective in the air and positionally solid, with plenty to learn, and he communicates very well with his teammates.

Christensen has slotted right into the Chelsea defence effortlessly when called upon

The signing of Rudiger and the emergence of Christensen really puts pressure on the place of Gary Cahill in this Chelsea line-up.

Can not take anything away from the highly successful career Cahill has enjoyed, but times look to be changing at Chelsea, and so might the role of Gary Cahill at the club.