Image source, Getty Images

Today's match will be the first meeting between these two countries - though there is a tenuous link via the 1980 Olympic Football Tournament, fittingly held in the Soviet Union.

The game played in Minsk (now the capital of Belarus) ended 3-2 to Yugoslavia, which Serbia was then a part of.

I said it was sketchy!

Serbia failed to qualify for the group stages in Brazil and only lasted three games in South Africa four years earlier.

Costa Rica were knocked out by the Netherlands in the quarter finals in Brazil in 2014 after topping a group containing England, Uruguay and Italy.

Image source, Getty Images

Right back to today at the Samara Arena...

G: Not quite Brazilian... the legend that is Norman Whiteside!

Craig: Norman Whiteside from Northern Ireland in 1982. Great World Cup with a few Home Nations competing

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It was Northern Ireland's Norman Whiteside of course. Who became the youngest player in World Cup history by appearing in a group stage game against Yugoslavia at the finals in Spain.

He got booked as well for his troubles during a 0-0 draw.

Some player though!

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Also yesterday Kylian Mbappe became the youngest ever France player at the World Cup at 19 years and 178 days.

While in the same game Daniel Arzani has become the youngest player to make a World Cup appearance for Australia at 19 years and 163 days.

But that's a long way off the overall record which stands at 17 years and 41 days and was set on this day back in 1982.

No doubt it was some Brazilian starlet....

Before we get going on today's agenda we've put together a perfect reminder of everything that happened yesterday - when five penalties were awarded and VAR dominated the agenda.

We have all the goals and talking points, as well as some of the more lighthearted moments in a World Cup catch-up video for you.

Image source, BBC Sport

So what have we got lined up for you?

We're kicking-off with the first game of the day, Costa Rica v Serbia before the big guns come into play.

Both Germany and Brazil are in action later today.

You will be able to follow all the games here, on BBC Radio 5 live and watch world champions Germany take on Mexico, live on BBC One from 15:30 BST.

I can't wait.

Hello. It's day four of the World Cup so that means another veritable football feast.

So far we've had eight games, 21 goals and some standout performances to boot. What's coming up today?

Hopefully more of the same.