John Murray
BBC Football Correspondent on 5 live

We're getting to the stage where one goal might be enough to win this cup tie.

Image source, Getty Images

Nottingham Forest bring on Cafu for Philip Zinckernagel with 15 minutes of normal time remaining.

Gabriel Martinelli can have no complaints with that booking. It's a desperate tackle to halt Djed Spence's progress down the right.

A wayward pass by Alexandre Lacazette sees an Arsenal attack break down. It's proving a rather frustrating evening for Mikel Arteta's side.

There's a problem for Philip Zinckernagel in the middle of the pitch which sees play temporarily paused, he's holding his shoulder but it looks like he's good to continue.

Matty AFC: Holding defensively has played a 7 or 8 out of 10. On the ball, he's been a 3 at best. Really poor decision making from him today.

Lewis Grabban's first involvement sees the striker earn a corner for his side, but it's wasted by the hosts.

Alexandre Lacazette comes on for Arsenal.

Teenager Charlie Patino makes way.

Eddie Nketiah fires wide from a difficult angle as Arsenal look to assert themselves.

Mikel Arteta is going to respond with a change of his own...

Image source, Reuters

And here is that change.

Lewis Grabban, with 10 goals this season, replaces Keinan Davis up top.

Michael Brown
Former Leeds midfielder on BBC Radio 5 Live

It's probably time for Lewis Grabban to lead the line for Forest.

Kienan Davis makes up good ground for his side but he doesn't see the run of Jack Colback down the middle and the attack fizzles out.

Midway through the second half and Forest must really fancy their chances of an upset here.

No VAR at the City Ground of course. I'm sure they would have taken a very close look at that incident had this been played at the Emirates.

Good save!

It's a really good free-kick from James Garner, who whips his free-kick towards the top left corner, but Bernd Leno gets two strong gloves behind it.

Forest want a penalty for a push by Bukayo Saka on Jack Colback in the aftermath but referee Craig Pawson waves play on. It's a very clumsy challenge by Saka...

Gabriel Martinelli concedes a free-kick about 25 yards from the Arsenal goal. It's central, and very inviting. James Garner to take.

Here's what Kidderminster Harriers manager Russell Penn had to say on BBC Radio 5 Live after his sixth-tier side were drawn against Premier League West Ham in the fourth round:

"This is what the FA Cup dream is all about.

"I sweated hot and cold all day worrying about the draw. You just want that plum tie, to be rewarded for what we did yesterday and we got that.

"I think my phone will go into meltdown tonight. I was so proud last night, first and foremost for the players, club, chairman and fans. Everyone deserves it.

"The chairman is buzzing, he is over the moon. Did we expect to win? No, we thought we had a chance but we are shell-shocked. We deserved the victory and the chairman was like the Grinch at Christmas - his smile went from ear to ear.

"I will be going up against one of the most respected British managers, which is fantastic for me. I know he respects the competition, the lower leagues and West Ham are on the up. What a tie – I am so excited. We will welcome him with open arms, and his squad, and we cannot wait.

"Hopefully we can write some more history. The staff tell me about the 1994 cup tie and to mirror it 27 years later – what an achievement. It’s probably a bigger achievement this year.

"We have to come down to earth with a game on Tuesday, but I want them to enjoy these nights. Then it is straight back to work tomorrow."

Mickey Wallis: Nketiah isn’t even good enough to trouble Nottingham Forest. What makes him think he should play every week? Where’s the urgency from Arsenal? Extra time is a disaster with Liverpool and Spurs next week

That's a big chance, but Eddie Nketiah makes a real mess of it!

The Arsenal striker is picked out by a cross at the far post but rather than attack it with his head, he ends up chesting the ball back across the face of Brice Samba's goal.

Image source, Reuters

Corner to Arsenal. Can they do anything with this?

Nope. It's met by Kienan Davis at the front post with a big header.