Swansea have the first sight on goal as Bersant Celina slips a through ball to Wayne Routledge, but the winger is offside so his shot saved by Alex Smithies woudn't have counted anyway.

I make it 10 seconds for the first foul. Cardiff's Joe Bennett on Swansea's Andre Ayew.

Not a bad foul, but that's the tone set for what should be a full-blooded derby encounter.

Referee Tony Harrington blows his whistle and the south Wales derby is under way, to huge roars all around Cardiff City Stadium.

Here we go!

Gareth Vincent
BBC Sport Wales at the Cardiff City Stadium

Sunday mornings are not usually as loud as this.

Around 2,000 Swansea supporters have made the trip to Cardiff, among them Sheffield United striker Oli McBurnie.

They are making plenty of noise - and the home crowd are responding in kind as kick-off approaches.

Before the match kicks off, there will be a minute's applause to remember former Cardiff City players Alan Harrington and Chris Barker.

Former Wales defender Harrington died on 23 December at the age of 86 while Barker, who helped the Bluebirds win promotion to the second tier in 2003, died on New Year's Day at the age of just 39.

Gareth Vincent
BBC Sport Wales at the Cardiff City Stadium

Regardless of league positions, this game is as significant as it gets in any season for Cardiff City and Swansea City.

So it is a big day for both bosses to make some bold selection calls.

Neil Harris has reacted to a Championship thrashing at Queens Park Rangers by dropping five players including goalkeeper Neil Etheridge, while Steve Cooper has picked an attacking team spearheaded by teenage loan signing Rhian Brewster.

Swansea will want to dominate with the ball, but will Cardiff let that happen as they did in the return fixture back in October? It should be fun finding out.

Jason Perry
Former Cardiff player on BBC Radio Wales

There was no other team I wanted to beat more than Swansea when I was in that Cardiff City shirt.

Sheffield United striker Oli McBurnie is once again in attendance at the south Wales derby having left Swansea in the summer.

He's joined by MMA fighter Brett Johns as well as injured Swans centre-back Joe Rodon and his brother Sam.

Image source, Getty Images

It's been quite a week for Rhian Brewster.

Last weekend he played for Liverpool in a Merseyside derby, helping a young Reds side beat Everton 1-0 in the FA Cup.

Brewster then joined Swansea on loan for the rest of the season, reuniting with his former England Under-17 boss Steve Cooper.

The 19-year-old goes straight into the Swans' starting line-up today, into the cauldron of a south Wales derby at Cardiff City Stadium.

Image source, Huw Evans Picture Agency

This fixture has served up its fair share of drama over the years.

There have been high-scoring draws, red cards, hostile atmospheres, home and away victories for both sides and last-minute winners.

One of the most memorable late strikes came here at Cardiff City Stadium in 2010, when Michael Chopra gave Cardiff a first win in nine meetings with Swansea to spark delirious celebrations among the home crowd.

Who will be the hero today?

Image source, Huw Evans Picture Agency

Cardiff and Swansea first played each other back in 1912 - the Swans' first competitive fixture - and it ended in a draw.

That was a sign of things to come in this fixture, which has proved too tight to call on several occasions.

In fact, although Cardiff and Swansea have played a total of 61 league games against each other, neither has managed to complete the double of winning both home and away matches in any given season.

Having triumphed 1-0 at the Liberty Stadium in October, Swansea have the opportunity today to become the first team to do the south Wales derby double.

And as you can read in this piece with the two managers, Steve Cooper and Neil Harris both know that history beckons today.

Rhian Brewster goes straight into Steve Cooper's side having signed on loan from Liverpool this week as one of three changes to the team which began Swansea's last league game against Charlton 10 days ago.

Bersant Celina and Ben Wilmot are recalled as Yan Dhanda, Borja and the injured Mike van der Hoorn miss out. Another new signing, Marc Guehi, is on the bench.

Image source, BBC Sport

The big team news for Cardiff City is that goalkeeper Neil Etheridge has been dropped.

Having made eight changes for last weekend's FA Cup draw with Carlisle, manager Neil Harris has rung the changes once again, making five alterations from the team thrashed 6-1 at QPR in the Championship on New Year's Day.

As well as Etheridge, the other players dropped are defenders Aden Flint, Sol Bamba and Jazz Richards and midfielder Will Vaulks.

In their place come goalkeeper Alex Smithies, defenders Sean Morrison, Lee Peltier and Joe Bennett and winger Gavin Whyte.

Image source, BBC Sport

Cardiff will be looking for some revenge this afternoon having lost the first south Wales derby of the season at Swansea in October.

Neil Warnock was Cardiff manager at the time, and he was left frustrated by a lacklustre Bluebirds performance as the Swans deservedly took the points thanks to Ben Wilmot's goal.

Neil Harris, who took over from Warnock in November, will hope for a much more convincing Cardiff display today.

Image source, Huw Evans Picture Agency

Image source, Huw Evans Picture Agency

It's Bluebirds against Swans, Tiger Bay versus the Gower, Clark's Pies or Joe's Ice Cream... it's Cardiff City v Swansea City.

Welcome to Cardiff City Stadium for the 109th south Wales derby, as Cardiff host Swansea in the Championship.

The visitors have the edge as far as league standings go, currently in eighth spot, four points and five places ahead of their rivals.

But this game is about much more than Championship points. For both sides, this is the match which matters most.