Croatia have an attack within 10 seconds but their cross is cleared.

Chris Bevan
BBC Sport at Al Janoub Stadium, Qatar

Image source, BBC Sport

There's more Japan fans here than there are from Croatia - but the competition for the biggest flag is a bit one-sided.

Image source, BBC Sport

The least predictable World Cup last-16 tie begins. Who's going to win? I don't have a clue.

Alan Shearer
Former England striker on BBC One

Japan are going to have to come out and play a bit more. Nineteen of the 26-man squad play their football in Europe which is why they are getting better and improving.

Can you imagine the reaction already back there? Japan are getting better all the time.

Niko Kranjcar
Former Croatia midfielder on BBC Radio 5 Live

We do still believe that we can play better but at the end of the day in all three of those games we played, the midfield that we have is the best three midfield players in the World Cup [Mateo Kovacic, Marcelo Brozovic and Luka Modric] as a trio.

I think we will always dominate games but have struggled scoring goals and creating chances in the final third. We are a team that might not score much but we won't concede either.

National anthems = happening.

Alan Shearer
Former England striker on BBC One

I know they scored four against Canada but in the other two games against Morocco and particularly Belgium, Croatia looked slow and ponderous up front.

Twenty nine shots in the three games but 13 of those were against Canada so there is going to have to be a big improvement today against this Japan side.

Ashley Williams
Former Wales captain on BBC One

Croatia are very good, the strength is in the midfield. They've got so much experience in there. They control it, they never panic, they're patient. Sometimes you can't get near them.

If they go a goal down like the Canada game, there is no panic at all. They are so strong in that midfield area that they just wear other teams down.

Simon Gleave
Head of sports analysis, Nielsen Gracenote

Japan's players are fouled against the least with only 21 fouls committed against them in their first three matches.

Ko Itakura and Senegal's Idrissa Gueye are the only players to reach the last 16 who were shown two yellow cards during the group phase.

Croatia were the most accurate shooters in the group phase, getting 55% of their goal attempts on target.

They have made the least use of their 26-man squad, selecting only 16 of them to play so far.

Japan will "fight like samurai" today, says defender Yuto Nagatomo.

The 36-year-old is at his fourth World Cup.

"Before battle, the samurai would polish their weapons and refine their technique, but if they were scared in battle, all that would count for nothing," he said.

"It's the same as football. Of course tactics and technique are important, but if we're scared, it doesn't matter how much we've trained over the past four years because our technique will be no use.

"The most important thing is to have courage."

The FC Tokyo full-back said he still thinks about their last-16 collapse to Belgium in 2018.

"The past four years have been tough for me but I think we have all overcome that and improved as players," he said.

"I have been playing for Japan for almost 15 years and as far as I can see, this is the strongest team we've ever had at the World Cup."

Rio Ferdinand
Former England defender on BBC One

Josko Gvardiol has been my favourite defender to watch in the tournament so far. Great presence, he's happy for the battle, physical and he's got a wand of a left foot. He's got pace as well.

Comfortable off either foot and he's comfortable running out of defence with the ball. He has youth and fearlessness. Quick feet for someone of his size as well. For me, everything about him has been so positive.

This is probably the most even tie in the whole last 16, where it is not at all obvious who is going to win.

I'd say Portugal v Switzerland is the next closest one but the Portuguese are definite favourites.

We all expected the Netherlands, Argentina, France and England to go through from the first four games - and you'd fancy Brazil and Spain to qualify too.

Niko Kranjcar
Former Croatia midfielder on BBC Radio 5 Live

I will go as far to say say that [Croatia and Leipzig player] Josko Gvardiol will be the best defender in the world. I honestly genuinely think that.

He is only 20 years old and playing with such maturity. Obviously if things like injuries don't happen I think his ceiling is miles away. The most impressive thing is his maturity at such a young age.

Image source, Getty Images

Image source, .

In case this game goes to penalties, here's the guide on how to take one in a World Cup shootout.

Written by a man who once scored a penalty against Shay Given (me).

Croatia (29 years, 330 days) name their second-oldest starting line-up in a World Cup game, after the third-place play-off in 1998 against Netherlands (30y 126d).

They feel like they always have quite an old team.

Rio Ferdinand
Former England defender on BBC One

Japan won with unity, with spirit. The Germany game where they came from behind showed them that they could really go on and do something in this tournament.

In those moments, they have been calm, changed formation and shown that they have had tactical flexibility. Substitutes have impacted the game for them.

They haven't had to do it with loads of possession, they have been really clinical when they've had the opportunities. They'll be looking for more of that today.

Image source, .

I like the new five substitutions rule, and I think it's the right thing to do with the amount of games now and the intensity of modern football.

If your players are tired and have been chasing the ball all game, you can restock the energy in key areas in defence and midfield to ensure your intensity doesn't drop.

It is down to all the coaches to use what they have got on the bench to make an impact, whether it is by trying to be more courageous - like Japan have done twice now - or to maintain your defensive stability.

One of the clever things I've seen with some of the sides who have got a surprise result in Qatar is that they know when to have a breather and be compact as a team.

So, while it was Japan's high press that got them back in the game against Spain, and they were still making runs in behind Germany's defence late on in that game, they did both things in spurts rather than for 90 minutes. That is down to the coach.

Watch and listen on the BBC

This game is on BBC One and BBC Radio 5 Live - both available on this page.

Build-up on both has already started.

Image source, Reuters

Luka Modric makes his 159th international appearance for Croatia today.

The 37-year-old has appeared in four World Cups and four European Championships.

That is two-thirds of the tournaments the country have ever qualified for.

"This will not be the last tournament he will play for Croatia," said boss Zlatko Dalic.

"He is professional and in good shape, you can see how he is in training, working to improve himself. It's unprecedented.

"We will need Luka for some time more in the future."