James Justin's attempt was Leicester's first shot of the second half, having had 11 in the first half.

Jermaine Jenas
Ex-Tottenham and Newcastle midfielder on BBC Match of the Day Live

James Maddison is a special player who does special things for Leicester and hopefully will do for England too in years to come. He's a different type to what we usually produce in that midfield area. Really comfortable on the ball, takes great free-kicks and creates a lot. He is a player that has got quality in abundance.

Pat Nevin
Former Chelsea and Scotland winger on BBC Radio 5 Live

The biggest problem for Brentford is they haven't created enough clear-cut chances. They've looked nice, been good to watch, they've probably had more of the game in this second half, but chances? Not many.

Marc Albrighton twists, turns and smashes a cross into Emiliano Marcondes to win a corner which James Maddison will take.

It's headed away at the near post, before Dennis Praet scuffs the follow-up well wide.

And here comes James Maddison. Leicester want to see this off.

It's Demarai Gray who is coming off.

Brentford make the change. Dominic Thompson is off with that cramp. On comes Rico Henry.

Emlyn Begley
BBC Sport at St James' Park

Image source, Getty Images

At least 3,700 Oxford fans have made the long trip north for this game.

If the game has indeed sold out, it may make this the largest attendance Oxford have ever played in front of, excluding three games at Wembley.

Among England's top scorers and pushing for promotion from League One, Karl Robinson may have preferred this game a few weeks ago - since they have won only once in their past five games.

The last time they reached this stage of the FA Cup was in 2017 when they faced Newcastle. And won. 3-0.

This is a much stronger Newcastle than they faced then - but the hosts will have to be on their toes to avoid the fate of West Ham, who were smashed 4-0 by Oxford in the EFL Cup earlier this season.

Harry Birch: Would love to see Jack and his mate Alex go the whole way through the cup this year, have loved following it so far

A bit of cramp creeping in for Brentford's Dominic Thompson. His team have worked hard in the second half and this is the closest they have come.

Joel Valencia is getting into some nice positions on the right. Brentford work it out of the corner well but a sloppy pass from Dru Yearwood gives away possession.

Leicester break down the right and James Justin's curling effort is deflected away by Julian Jeanvier.

Image source, Getty Images

Five changes for Birmingham from the side that started the 1-1 draw with Middlesbrough on Tuesday.

There's a start for 16-year-old midfielder Jude Bellingham, who has been linked with a move to Manchester United.

Bellingham is Blues' youngest ever player - and can only sign a full-time deal when he turns 17 in June,

One change for League One Coventry as former Chelsea youth player Zain Westbrooke returns to the side.

About 20 minutes left. Can Brentford find an equaliser? They have probably been the better team in this half.

Mads Roerslev doesn't react to a header and Marc Albrighton gets there in front and wins a throw-in.

Albrighton then pulls it back for Hamza Choudhurt on the left but the midfielder slips it inside straight to a defender.

Jermaine Jenas
Ex-Tottenham and Newcastle midfielder on BBC Match of the Day Live

He's done well today Kelechi Iheanacho. He's taken his chance brilliantly and held up the ball well at times.

Emlyn Begley
BBC Sport at St James' Park

Newcastle go strong as expected with on-loan Schalke midfielder Nabil Bentaleb making his debut.

Five changes in total from their dramatic 2-2 draw with Everton. Allan Saint-Maximin, Fabian Schar and Deandre Yedlin come in, as does keeper Karl Darlow.

Two changes for Oxford from their 1-1 draw with Gillingham. Elliott Moore replaces John Mousinho at the back, with Marcus Browne taking the place of Nathan Holland on the wing.

White font on a yellow FA Cup? Disgrace.

Southampton make four changes. Striker Danny Ings returns to the starting XI while Angus Gunn starts in goal. Kevin Danso and Jan Bednarek also come in.

Southampton XI: Gunn, Danson, Stephens, Bednarek, Bertrand, Højbjerg (c), Ward-Prowse, Armstrong, Redmond, Obafemi, Ings. Subs: Lewis, Yoshida, Romeu, Smallbone, Djenepo, Boufal, Adams.

No Christian Eriksen in the Tottenham team with his proposed move to Inter Milan seemingly moving closer.

Just the three changes for Jose Mourinho in total - Gedson Fernandes makes his first start while Davinson Sanchez and Japhet Tanganga come in for Jan Vertonghen, Ryan Sessegnon and Erik Lamela.

Tottenham XI:Lloris, Aurier, Alderweireld, Sanchez, Tanganga, Winks, Gedson, Lo Celso, Alli, Son, Lucas. Subs:Gazzaniga, Foyth, Vertonghen, Dier, Ndombele, Sessegnon, Lamela.

Here is that change.

A debut for Kiernan Dewsbury-Hall as Kelechi Iheanacho goes off.

Leciester just enjoying a spell of possession now after an onslaught of pressure from Brentford.

But a long ball forward doesn't reach Kelechi Iheanacho and he's about to come off now.

Sheffield United

Milwall make five changes from their 2-0 win over Reading last week. Matt Smith, who has plenty of FA Cup pedigree, starts up front.

Millwall: Bialkowski, M Wallace, Cooper, Smith, Ferguson, Pearce, Molumby, Brown, Mahoney, O'Brien, Mitchell. Subs: Sanford, Hutchinson, J Wallace, Romeo, Bradshaw, Skalak, Bodvarsson.

After making 11 changes in round three, Chris Wilder makes just five for this round. Billy Sharp keeps his place up front and 37-year-old Phil Jagielka comes in at the heart of defence.

Sheffield United: Henderson, Basham, Jagielka, O'Connell, K Freeman, Osborn, Norwood, Besic, L Freeman, Sharp, C Robinson. Subs: Verrips, Morrison, Egan, J Robinson, Clarke, Lundstram, McBurnie.