I tell you what, this is tasty. Ivan Rakitic trips Paulo Dybala, who waves an imaginary yellow card. It's actually Dybala who gets a flea in the ear from the ref. "Do not tell me how to do my job, young man."

All Juve so far, some trickery down the left. Boos from the home fans every time the men in black and white have the ball. The Italians are attacking the goal to the right as we watch on.

Image source, Reuters

I'm fairly certain Dani Alves missed the kick-off because he was shaking hands with everyone on the Barca bench...

Under way. Deafening.

Here they come. Remember, we're delayed by five minutes in Monaco.

Did you know that the Champions League theme was composed by an English bloke called Tony Britten?

It's being drowned out by jeers in Spain. Is it the fashion to do that now?

Flags flying in the Nou Camp, all home fans given something to wave in order to drum up the atmos. It's done the trick. Players are in the tunnel.

In Monaco, home fans raise a banner than says "BVB You Will Never Walk Alone". Lovely touch.

Image source, #bbcfootball

Barca have needed a decent right-back this season as well...

John Dunthorne: Different this time, last time PSG played like Cavaliers, Juventus will play like Roundheads. 0-0 or 1-0. Not enough! 

Marc Bartra won't only be on the Dortmund bench, he'll be delivering the final 30 seconds of the team talk before the players emerge from the dressing room.

How's that for emotion and motivation? I'd be a teary mess, nevermind going out to play a Champions League semi.

Should we expect a fired up Dortmund? 

On the other hand, Stade Louis II looks a bit like something from Star Trek. Space-age concrete looming over one side, towering arches behind the goal.

In the tunnel, a car has taken a wrong turn looking for somewhere to park underneath the stadium.

Kind of impressive, but in an entirely different way.

The Nou Camp is a sight, isn't it?

Awe-inspiring, seats rising high into the cloudless Barcelona sky, those at the top peering down from what must seem like miles above.

A wonderful, warm, spring evening. A later kick off allowing time for a meal and a drink beforehand.

They've got football-watching nailed on the continent.

Right, are you on top of all of that?

It leaves me to remind you of how to get in touch - tweet using the hashtag #bbcfootball, external or text 81111.

As Barca look to pull off the magnificent one more time - tell me about when you have completed a double comeback.

Common-or-garden one-time fightbacks are not welcome here. I want to know about the time you've defied the odds on Fifa, where your Sunday League team has come from 5-0 down or when you beat your dad at Monopoly after he got Park Lane and Mayfair. Twice.

The other thing to know about Dortmund is that Marc Bartra, the defender injured in last week's bomb attack, will sit on their bench tonight (not as part of the matchday squad, it should be stressed).

In the run-up to tonight, Barcelona pair Sergio Busquets and Jordi Alba visited their former team-mate as he continues to recover from the arm injuries he sustained.

Some App users may have to click the link to see this Tweet.

Image source, Rex Features

Dortmund welcome back Marco Reus after the midfielder missed the first leg with a hamstring injury, while Ousmane Dembele, who started in the 3-2 defeat, drops to the bench.

Dortmund: Burki, Sokratis, Piszczek, Ginter, Durm, Guerreiro, Weigl, Sahin, Reus, Kagawa, Aubameyang.

Image source, Rex Features

Monaco are without the influential Fabinho due to suspension - the midfielder missed a penalty in his side's first-leg 3-2 win in Germany. 

Defender Benjamin Mendy returns for the hosts.

Monaco: Subasic, Glik, Jemerson, Toure, Mendy, Bakayoko, Moutinho, Lemar, Silva, Mbappe, Falcao.

That's a curious one, right? Dortmund are saying their bus was held by police, but there's no reference to that from Uefa.

Either way, both sides have named their teams...

Right, we have it confirmed. The kick-off has been delayed by five minutes.

According to Uefa, it's because of a "late arrival".

If your German isn't great, that tweet is claiming that the Dortmund team bus was held by police for around 20 minutes "without justification".

The tweet claims that the kick-off has been delayed, but that is yet to be confirmed.

We do know that the players are now inside the stadium.

App users may have to follow the link to see more...

Before we get to the Monaco-Dortmund team news, there's some news coming from the French Riviera.

Remember, it was just over a week ago that the first leg in Germany was delayed for 24 hours after a bomb attack on the Dortmund team bus...