Robert Gallacher: Willian has been dreadful today. Sarri should have taken him off and brought Fabregas on - game is crying out for his creativity.

JavelBleach: OMG, if #WHU, external carry on missing Open Goals like that, they're going down! Worse than #Sakho, external yesterday!

Image source, AFP

The final roll of the dice from Maurizio Sarri. Off comes Mateo Kovacic, on goes Ross Barkley.

Bradley Allen
Ex-QPR striker on BBC Radio London

Firstly he just about held his position. It was lovely from West Ham, they were patient and didn't rush it.

Yarmolenko's drifted in and he must hit the target. It's a gilt-edged opportunity.

Will that haunt West Ham?

Had to be. Had. To. Be.

Andriy Yarmolenko has his head in his hands. He knows.

The Ukraniain is perfectly picked out at the far post by Robert Snodgrass, but, unmarked, he contrives to glance wide of the Chelsea goal from six yards.

An absolute eyesore of a miss. The injured Marko Arnautovic is off his feet in disbelief in the posh seats.

A free-kick, 30 yards-plus from the West Ham goal but central.

Will it be the sharp-shooter of Willian?

Nope, the blunderbuss of David Luiz wins the argument.

The central defender sends a low, skidding shot into the arms of Lukasz Fabianski. Never quite caught it.

Arsenal make seven changes to the side that beat Vorskla Poltava in the Europa League on Thursday, but Lucas Torreira is the only player to come into the side that won at Newcastle last time out in the Premier League. The midfielder replaces Matteo Guendouzi.

Richarlison returns for Everton after his three-match ban for being sent-off at Bournemouth.

Michael Keane also returns from injury, with Tom Davies coming in to captain the side as part of three changes to the XI that started the defeat by West Ham last Sunday.

Cenk Tosun, Mason Holgate and Morgan Schneiderlin all drop to the bench.

Bradley Allen
Ex-QPR striker on BBC Radio London

These are the type of fixtures if you [Chelsea] are going to be in the mix up, that you need to win.

You need to win the London derbies.

We're at the stage where Chelsea are dominant with the ball but West Ham could get that one breakout. Are they going to be able to involve Perez enough?

Snodgrass is on now and offers a bit more balance.

West Ham whip off the busy Felipe Anderson, who looks like he might have run low on battery, and bring on Robert Snodgrass.

Image source, Reuters

A Adeni: Chelsea are being patient but a goal now is very much needed. Need to get into the wider areas & behind their defenders. Let’s give Morata a chance

Andy M Morley: Final half hour of #WHUCHE, external interesting for Chelsea. Scholari’s Chelsea started wonderfully in 08-09 and then opposition realised there was no Plan B only a Plan A I believe Sarri has a Plan B but hoping to see different rather than like-for-like subs and a win

Centre-back Antonio Rudiger's hamstring has sprung.

He is off and Gary Cahill, who said earlier in the week that he would be looking for a move away from Chelsea and first-team football in January, is on for his first appearance of the season.

Chances! Plural! For Chelsea.

The first comes as Willian threads in a ball off the right flank for Eden Hazard. Tight angle and the Belgian opts for the ambitious backheel to Alvaro Morata rather than trying to take the ball round Lukasz Fabianski.

A West Ham defender nips in to intercept.

A second follows shortly after as Andriy Yarmolenko miscontrols in his own box. Morata is onto it in a flash, getting to the ball just before Fabianski, but his attempted chip hits the West Ham goalkeeper in the face.

Image source, Getty Images

And a change up top for the Hammers as well. Lucas Perez replaces Michail Antonio.

Alvaro Morata, one goal in six games this season, is on in place of Olivier Giroud.

That was more like the diet that Olivier Giroud thrives on.

N'Golo Kante slings in a cross to the near post and the Frenchman almost gets on the end of it.

That is Giroud's last contribution though...

Declan Rice gives away a free-kick as Mateo Kovacic beats him to the ball and the West Ham youngster gets only ankle.

Can Willian find a telling delivery?

No, he can't. West Ham clear with ease.

Chelsea need to stretch the West Ham defence in new ways. Over to you Maurizio.

Bradley Allen
Ex-QPR striker on BBC Radio London

West Ham are tiring a little bit, there are a few players warming up.

They've got options with Robert Snodgrass and even Ryan Fredericks.

Image source, PA

That is meat and drink for Lukasz Fabianski.

Cesar Azpilicueta's cross is an absolute dolly, devoid of whip, dip or intent.

Chelsea are struggling to break down West Ham.

Time to break Alvaro Morata and Ross Barkley off the bench?

Should do better.

David Luiz loses marker Declan Rice in a penalty-box crowd scene, but never gets over the top of his unchallenged header, sending Willian's corner flying well over from 10 yards out.

Try running your hands through that barnet in disappointment though.

Andriy Yarmolenko goes down in the Chelsea box as he attempts to control the ball under the attentions of David Luiz.

Nothing doing.

Felipe Anderson is probably better with the ball than chasing it.

The West Ham man gives away a free-kick and earns a yellow card as he leaves a lazy leg in on Willian.