Phil McNulty
BBC Sport chief football writer at Stamford Bridge

The first "Hazard Can I Have Your Shirt?" banner is brandished by a Chelsea fan behind the goal - blimey, give him a chance.

Image source, PA

A fine atmosphere inside the ground, and the game has started at full speed. Juan Mata has been heavily involved already. Interesting that Paul Pogba is playing from the left once again in this diamond. United are all over Chelsea, as Romelu Lukaku batters a volley miles over the bar following some penalty area pinball.

Absolutely terrific start from the visitors, tearing at the Chelsea defence at real pace, Paul Pogba and Juan Mata teeing up Romelu Lukaku on the left wing. He fires in a low cross which David Luiz, under scrutiny from Marcus Rashford, turns just past his own post!

The corner comes to nothing.

Image source, AFP

Martin Keown
Former Arsenal defender on BBC One

It looks like Juan Mata is going to play off the front. I am sure he has a mission to sit on Jorginho but be creative as well.

Juan Mata almost plays in Marcus Rashford straight from kick-off! The Spaniard is indeed at the tip of a midfield diamond. A proper number 10.

And we are under way!

Image source, Getty Images

There may be question maks over both sets of players and both managers but there's more than enough good players on the pitch tonight to muster a good game!

Let's hope so.

Jimmy Floyd Hasselbaink
Former Chelsea striker on BBC One

Surprise, surprise.

I think you will see an energetic Chelsea. It will be tight but I am going for Chelsea.

Phil Neville
Ex-Man Utd and England defender on BBC MOTD

I fancy Man United on the counter-attack. I am going for them to win.

A lot of people on social media seem aggrieved that Juan Mata is playing instead of Alexis Sanchez but the Chilean looks in horrid form doesn't he?

Anyway, here come the sides. No replays of course - a clean exit eithe way for one side tonight...

Phil Neville
Ex-Man Utd and England defender on BBC One

I wouldn't have played Alexis Sanchez tonight. He is not playing that well. The love of football he talks about - I don't see it.

I am not so sure he can get back to the level we saw at Arsenal.

Has Manchester United's Paul Pogba been persuaded to do some five-a-side moonlighting for the FA People's Cup?...

Don't miss your chance to play against 'Paul' and the rest of the Kloppelgangers!

Sign up here, external - either as a team or on your own - before midnight!

John O'Shea
Former Manchester United defender on BBC Radio 5 live

On N'Golo Kante playing further forward this season

That’s the question which keeps firing back at Sarri. If you’re a Chelsea centre-back, you’d be thinking 'why isn’t Kante in front of us?'

The confidence would grow in the team. I know Alonso is a good defender but he looks like he’s short of confidence. So does Azpilicueta.

Aaron Theaker: I've been a Napoli fan all my life! Sarri is a fantastic manager on his day but was stubborn to change his style. Meaning whilst we played attractive football, we dropped a lot of points from teams we should have been beating. Not a great style for the premier league

Problems in both camps then...

Jimmy Floyd Hasselbaink
Former Chelsea striker on BBC One

Last year Chelsea were playing horrific. They were playing counter-attacking football and Sarri has changed the style totally but the balance has to be right in midfield. That is not there. The intensity is not high enough.

In the first 15 matches they were a pressing team. That has gone.

Lee Dixon
Former Arsenal and England defender on BBC Radio 5 live

It's a surprise that Alexis Sanchez isn't playing. You're expecting him to get in at some point. He'll be frustrated. When he left Arsenal he thought it would be easier than it was to get into the side. He's been disappointing when he's gotten into the side.

It's looking like he's starting to lose the will. We saw that at Arsenal when he downs tools he turns into a very average player.

He was the main man at Arsenal. He wandered around the dressing room like that and caused problems. He's come into a stronger dressing room at Man Utd where he's not the big fish.

Chris Sutton
Ex-Premier League striker on BBC Radio 5 live

On Man Utd playing Sergio Romero instead of David de Gea

It's really odd, bearing in mind Ole Gunnar Solskjaer said not long ago about how important it is to win trophies.

If you want to win the game, play your best goalkeeper. If Romero makes a mistake... They haven’t named Ole as permanent manager, it could cost him the chance to get the job.

Alan Shearer
Former England captain on BBC One

Whoever comes in as manager of Chelsea knows they are not going to get time. They have to deliver. In the past it has worked. When a manager hasn't got results he has gone and another man has come in.

I believe a manager's job is hard enough and Sarri should be given time but that is not the rule at this football club

In the defeat against City they looked confused. They didn't know whether to press or sit.