Should be 2-0. Manuel Lanzini is fed the ball in the box following a swift Hammers break, but he can only side foot an effort softly wide of goal.

Blackpool overcame Premier League opposition in the last round by beating West Brom and they look confident against Brighton so far as Gary Madine is almost through on goal but he hesitates, allowing the defence to recover and his shot is blocked.

Swansea have started sharply. Matt Grimes moves it out right to Wayne Routledge but his cross is dealt with.

Conor Hourihane then comes sliding in to concede a corner as Forest break at the other end with Luke Freeman.

West Ham look bang up for this.

Pablo Fornals goes in again in the box, this time looking to steer a header on goal. He is challenged, though, and nods wide.

Remember, you can follow this game live by clicking up at the top of this page.

Billy Sharp is in the mood. United press high and strip Plymouth of the ball, two quick passes send Sharp into the area, he shoots and it's turned away for a corner.

Fine recovery tackle.

Michael Brown
Former Sheffield United midfielder on BBC Radio 5 Live

Sheffield United are moving it around nicely, they want to play and we're seeing a bit of confidence from them. United are pressing really, really high.

Nice bright start from the hosts as a John Fleck cross goes right across goal and is hooked away from inside the six-yard box.

Billy Sharp then threatened in behind but the late offside flag came up to save Plymouth.

Looks a bit sandy does the pitch at Oakwell. South Yorkshire has taken a fair old battering from the weather of late, so it's no surprise to see the surface showing some wear and tear.

Nothing of note to report just yet from either side.

James Husband defends well to prevent Percy Tau from getting a shot off after the Brighton man had brought down a long ball from the back.

Lewis Dunk then heads just over from a corner. Good start by the hosts.

There's an early free-kick for Conor Hourihane on the left. He whips it in dangerously but it comes all the way out to the far side.

Off we go in all six matches. Where's the first goal coming from?

Barnsley have won just one of their past 16 meetings with Norwich in all competitions (D4 L11), losing 1-0 at Carrow Road in the Championship earlier this month.

Norwich have won two of their three FA Cup ties against Barnsley, with this the first such encounter between the sides since a 1-0 win for the Canaries in January 1992.

Barnsley are looking to reach the FA Cup fifth round for the first time since 2012-13, with the Tykes losing against Portsmouth at this stage of the competition last season.

Norwich are looking to reach the FA Cup fifth round in consecutive seasons for the first time since 1990-91/1991-92.

Cauley Woodrow has scored five goals in his five FA Cup appearances for Barnsley, netting a penalty against Tranmere in their 2-0 victory in the last round.

Here's a reminder of the fifth round draw, concerning these games:

• Manchester United or Liverpool v West Ham United or Doncaster Rovers
• Sheffield United or Plymouth Argyle v Millwall or Bristol City
• Barnsley or Norwich City v Chelsea or Luton Town
• Swansea City or Nottingham Forest v Cheltenham Town or Manchester City
• Brentford or Leicester City v Brighton & Hove Albion or Blackpool

West Ham are unbeaten in their last five meetings with Doncaster (W2 D3).

Doncaster have won just one of their last 16 FA Cup games against top-flight opponents (D4 L11), beating QPR 1-0 in the third round in 1984-85.

They are looking to reach the FA Cup fifth round for the second time in three seasons, having not previously reached that stage since the 1955-56 campaign.

Doncaster have won their last three away games in the FA Cup, their longest ever winning run on the road in the competition.

Leon Osman
Former Everton midfielder on Final Score

Sheffield United have given themselves so much to do, they'e only got five points and the closest team to them is already in the teens so it will be really big ask to keep them in the Premier League this year and I think that's why today we're seeing a strong starting XI - they will want to keep some momentum going.

Kyle Walker and Kevin de Bruyne will be missing for Manchester City's FA Cup fourth-round tie at Cheltenham.

Walker went off in the 2-0 win against Aston Villa on Wednesday after hurting his hip.

The full-back is expected recover after the cup tie.

Midfielder De Bruyne has been sidelined for up to six weeks with a hamstring injury, while striker Sergio Aguero misses out after testing positive for coronavirus.

The Argentina international confirmed the news on Thursday when he revealed he is self isolating while he recovers from the virus.

Image source, Getty Images

Millwall have lost just one of their last nine meetings with Bristol City in all competitions (W4 D4), going down 2-1 at home in April 2019.

Bristol City won their only previous FA Cup meeting with Millwall, winning 1-0 at home in November 1997.

Millwall lost at home to Sheffield United at this stage of the FA Cup last season - the Lions haven't lost consecutive home games in the competition since a run of three between January 1946 and January 1948.

Bristol City have reached the fifth round of the FA Cup in just one of the past 19 campaigns, doing so in 2018-19 before being eliminated by Wolves.

Leon Osman
Former Everton midfielder on Football Focus

I think he's getting back to the David Moyes we saw at Everton - when you think about West Ham if they play well they can win games but when they had an off day they were a bit of a pushover. But I think Moyes has got them playing now and they could go on a really good run. We're seeing a real strength of character in this team.