Gabriel Martinelli shoots just wide for Arsenal, with Manchester United goalkeeper Andre Onana taking too long with the following goal kick and seeing yellow for supposed time wasting.

Image source, Getty Images

John: That's why you need VAR. Real time looked like a clear pen, one replay and you can see it wasn't.

Garreth: Really odd decision to overturn that. I can see the ref either giving that or not, but was it a clear and obvious error? No.

Adrian: What exactly is the difference between Rashford’s penalty last week and Havertz’s? Both running at full speed, both clipped with very little contact (but enough that at speed you would be fouled). One given, one not. Make it make sense!

Two big changes for Manchester United. On Harry Maguire, off Lisandro Martinez. On Rasmus Hojlund, the £72m new signing, and off goes Anthony Martial.

Image source, Reuters

Lisandro Martinez is late to the ball, catches Eddie Nketiah and sees yellow for the challenge.

Martinez may have hurt himself doing so and Harry Maguire gets ready.

What a story it would be if the England international, who was stripped of the United captaincy and not featured this season, makes a crucial impact.

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Phil McNulty
BBC Sport chief football writer at Emirates Stadium

Arsenal's fans are understandably very, very frustrated but that looked like one VAR got right. Still level.

Should Arsenal have had a penalty then? Thumbs up for yes, thumbs down for no.

Matt Upson
Former Arsenal defender on BBC Radio 5 Live

It looked more like a penalty in real time but in slow motion it looks different. When Kai Havertz is running through it doesn't need a lot of contact to bring him down.

For me, there is enough of clipping heels there. But there is contact.

Anthony Taylor, after checking the incident, changes his mind, decides the challenges from Aaron Wan-Bissaka and Casemiro on Kai Havertz weren't enough to cause him to fall down.

No penalty for Arsenal, we stay at 1-1. That won't be the last we hear about that.

Image source, Reuters

Matt Upson
Former Arsenal defender on BBC Radio 5 Live

It's lovely play. It's all about the touch from Havertz. They just clip his heels and it looks like a penalty to me.

Anthony Taylor jogs over to the pitchside monitor to have a look. This could be bad news for Arsenal.

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Kai Havertz goes down under a combined challenge from Aaron Wan-Bissaka and Casemiro. Penalty to Arsenal.

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Gabriel Martinelli takes a free-kick to the left of the penalty area and Kai Havertz helps it on.

Matt Upson
Former Arsenal defender on BBC Radio 5 Live

Big chance for Manchester United. It is parried out by Ramsdale and then the block. That is brilliant defending.

A first chance of the match for United's Anthony Martial, but Aaron Ramsdale gets two hands to the shot from a tight angle with it then falling to Marcus Rashford.

But he can't get his second goal of the match as his shot bounces off Ben White's leg and goes behind.

Denzil: We need a legendary debut performance from Hojlund to spice up this game!

Steve: BIG mistake from ETH there, not to bring on Hojlund. Please don't wait for the Gunners to score again, to do this!

Dan: I think everyone needs to stop talking about Arsenal being title contenders. Not because they aren't title contenders, but because everyone is being so negative during games because they expect us to be winning 3-0 within 45 minutes and be completely dominant. Let's all calm down, yeah? Better to start slow and find a rhythm than to come out the gates and lose steam at the business end of the season like last year!

Eddie Nketiah gets the ball of Kai Havertz and strikes at goal but it is blocked by the United defence.

Matt Upson
Former Arsenal defender on BBC Radio 5 Live

If you are going to play that short ball and then clip it long, you are giving yourself an issue if you don't win that header. The pitch becomes so stretched and you're so open to being exploited.

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Ben White hits a first-time cross into the danger zone, but his opposite right-back Aaron Wan-Bissaka does well to rise and head it clear.

Allan: It's been pretty one-sided of course but there is such a huge difference when Onana has the ball vs how panicked they were when De Gea had the ball in the same fixture last year. Even seems Arsenal have stopped pressing so high because of it

And we're back for the second half. No changes at the break.