Allan Preston
BBC Scotland summariser at Murrayfield

That's it for poor old Steven Naismith. He's grimacing with pain as he leaves the field for a second time. Danny Amankwaa is on in his place.

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Uh-oh. Hearts forward Steven Naismith goes down with no one near him and looks to be in a spot of bother. The physio is on giving his knee a squeeze.

Now he's walking off and appears to be okay.

It's pretty fiesty, with Tom Rogic the latest player to be chopped down in a congested midfield.

Referee Willie Collum is quick to reach for his cards as Steven MacLean bangs into Mikael Lusting as the ball drops out of the bright blue sky.

Lustig goes down clutching his face but TV replays show it was the ball that caught him in the coupon and not the arm of the Hearts forward.

Here we go. Murrayfield looks great in the Edinburgh sunshine and the 60,000 or so fans are making quite a din.

Just a few minutes until kick-off...

Holders Celtic are going for three in a row, which would be a seventh trophy out of seven under the command of Brendan Rodgers.

Rangers are the last team to celebrate three successive successes in the competition, back in 1989.

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Hearts manager Craig Levein on Sportsound: "Callumn Morrison has played a lot of games. He's got a cartilage problem with his knee, which flares up every now and then. That isn't the reason that I've left him out.

"Peter Haring is fine. He trained on Friday, didn't do everything but got through it reasonably well, trained yesterday and had no reaction. I feel confident that he's ready to play.

"Today, I'm looking to start now probably our most experienced players. The occasion is really important. I just hope that those guys will be able to handle the occasion. Throwing a couple of youngsters in at this minute in time, I decided against that.

"We've gained confidence [since we last played Celtic]. I think we are a better side. The difference between Celtic's best players and their substitutes and the rest of the squad, the gulf isn't that big. They're able to bring in able replacements.

"I'm interested to see what the atmosphere's like here today. I believe there's going to be 60,000-odd here. It gives me a great sense of pride to know that for a semi-final we've sold nearly 30,000 tickets. That tells me that we've got a lot of people who are excited about coming to watch our team."

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Celtic manager Brendan Rodgers on BBC Radio Scotland: "We came and trained here during the week and it's a lovely stadium. It's a great occasion. It's a wonderful venue to come to.

"Scott Bain has played in the cup games, so it's fairly simple, he's a goalkeeper I rate very, very highly. Craig Gordon has played a lot in the last couple of years but this year I wanted to make sure we had a number two who can push. It's important he feels my trust to put him in the team.

"The other changes, we've had a number of injuries and players returning from suspension but it's a very strong side.

"Kristoffer Ajer has shown up well, fantastic in the run in the team he had, he doesn't make many mistakes, very concentrated for a young player and a tall player so good in the air for set-pieces and strong. He's fit enough to play.

"There's no definitive time on Leigh Griffiths coming back. Scott Brown will be another couple of weeks."

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Pat Bonner
Former Celtic goalkeeper on BBC Sportsound

Allan Preston
BBC Scotland summariser

SPFL chief executive Neil Doncaster defends the rather chaotic scheduling of today's matches on BBC Sportsound.

"The game is all about the fans and we're going to have a combined attendance of over 100,000 and that's great. The focus turning now to football is a welcome relief," he said.

"Ultimately, we inherited the arrangements for the hosting of games at Hampden from the merger with the Scottish Football League in 2013, we inherited a contractual obligation to play any semi-final with expected crowds of more than 20,000 at Hampden.

"We asked the question and were told, no, you have a contractual commitment to play both games at Hampden. It was entirely manageable from the point of view of Hampden Park Ltd and Police Scotland. In those circumstances, we had no option. We asked the question, we pushed, we were told the games had to be played at Hampden.

"It was only when the SFA subsequently came in, chief executive Ian Maxwell offered the facility to take one game away from Hamdpen.

"We very quickly agreed terms with Hampden Park Ltd to take one game away and with Scottish Rugby to hold one game at Murrayfield.

"I don't think we could have done anything differently. I'm delighted that we've got to an outcome that better suits everyone."

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Hearts owner Ann Budge on Radio Five Live: "It's euphoric [being in the semi-final]. It has really taken the city by storm. We are absolutely delighted to be doing what we're doing. The fact we're going to have 30,000 supporters is a dream come true."

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Steven Pressley
Former Hearts and Celtic defender

Hearts seem to be a club brimming with confidence and belief at this moment in time, Craig Levein has done a wonderful job, especially this season.

He’s had to endure difficulties with the loss of some real key players. Christophe Berra is such an important player for Hearts.

Brendan Rodgers has done a brilliant job at Celtic. He’s a very organised and experienced manager that has great trust in players. He's got a remarkable record and he'll be desperate to keep that intact.

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Rangers completed an Ayrshire double to reach the national stadium, beating Kilmarnock 3-1 at Rugby Park before hitting four past Ayr United at Ibrox.

Alfredo Morelos scored four over those two ties but also picked up a yellow card each time, so the striker misses out today. Kyle Lafferty is cup-tied, so it will be interesting to see who gets the nod up front in their absence.

Aberdeen's reward for cuffing St Mirren 4-0 at Pittodrie was a trip to Easter Road and Hibs fans will have a few pangs of regret today after their side passed up several good chances and paid the penalty on penalties, with the Dons prevailing 6-5 in the shoot-out after a goalless draw.

Image source, SNS

Image source, SNS

So, how did all the teams get this far?

Hearts are the only side who started their journey in the group stage and they nearly made a mess of it by fielding an ineligible player in their opening win at Cove Rangers followed by a draw at Raith Rovers but they thumped Cowdenbeath and Inverness CT to top the section on goal difference.

Olly Lee scored the only goal as Dunfermline were edged out at East End Park and the midfielder was on target again as the Jambos found two late goals to sink Motherwell 4-2 at Tynecastle.

Celtic's route has been more straightforward, with the holders winning 3-1 at Partick Thistle and 1-0 at St Johnstone.

Leigh Griffiths scored in both matches but is missing with the flu - or on the run in Uzbekistan, or taken up a new career in scuba diving, according to wild rumour-mongering on social media.

Image source, SNS

Image source, SNS

Peter Houston
Former Scotland assistant manager on BBC Sportsound

Hampden, with its synthetic and grass hybrid pitch, will use the same field dimensions as Hampden.

Hearts have beaten Celtic twice on their tight Tynecastle park in the past 12 months but conceded seven goals in their past two visits to Parkhead.

But manager Craig Levein is confident his "more cerebral" team can cope with the wide open space.

"The team is slightly different to what it was last season," he said earlier this week. "We had quite good success against Celtic last season (at Tynecastle) because our game was all about running and energy.

"I don't feel it's the same this year, I think the players are a little bit more cerebral and understand more about the defensive shape than maybe we did last season.

"I think it was really just pure energy and effort last season. I think we have players who understand the defensive side of things a little bit better. There's not as much running, there's more thought, so the size of the pitch I don't think is as important this time round as it would have been last year."

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This is the first time Murrayfield has been used for a cup semi-final but it is not the first time Hearts have played here - or Celtic.

After the venue change, Celtic boss Brendan Rodgers said the rugby stadium was "certainly not neutral" since Hearts had played league games there last season.

However, Hearts only managed to win one of those four matches and the team is much-changed following a massive squad overhaul in the summer.

Hearts have played European ties at Murrayfield in the past and Celtic have done the same, playing two qualifying ties when Celtic Park was being used for the 2014 Commonwealth Games.

After a training session this week, Rodgers called Murrayfield a "beautiful, iconic stadium".

Scottish Rugby chief operating officer Dominic McKay on Sportsound: "We want to work with football and this is a great opportunity for rugby and football to work together.

"It'll be a cracker. I think it's good for Scotland. It's been a very special few weeks. We've done a lot in a short space of time.

"What we're going to see today is two great teams playing in an unbelievably special location and thankfully the weather's shining as well."