Stephen McGinn
Former St Mirren midfielder on BBC Sportsound

The pitch looks particularly tricky out there today, it's bobbling away for some players.

Adam Idah has the ball in the net, but the whistle had already gone as he dribbled out of play.

Another St Mirren corner is dealt with and Celtic look to break, but the hosts mop up.

Good period of St Mirren pressure ends with a corner as Mikael Mandron heads one off the back of Alexandro Bernabei.

Joe Hart punches away the set piece.

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A half chance for Dundee as the ball breaks to Lyall Cameron in the box after Aaron Donnelly tried a bicycle kick in the box.

His half volley was blocked behind. Two corners follow, the second coming to Donnelly at the back post but his header is wide.

Charles Dunne keeps Daizen Maeda at arm's length as the Celtic forward looks to run in behind.

An even start in Paisley.

Celtic corner as Callum McGregor's clipped ball is headed behind.

The away side take it quickly, in the style of their previous manager, but St Mirren hack clear.

Andy Burke
BBC Scotland at SMISA Stadium

Liam Scales took playing out from the back to a new level there.

The Celtic fans, and Pat Bonner in our commentary box, had a brief moment of panic that the ball was heading into Joe Hart's net before the keeper guided the ball away from danger.

Bold from Liam Scales, whose touch looks a wee bit heavy, but he manages to shift the ball to Joe Hart just in time.

On a bobbly pitch, that looked a bit dodgy.

St Mirren test Celtic's makeshift defence early as Anthony Ralston gets his head on a cross.

Away we go in Paisley, kick-off in Dundee will follow shortly.

Here come the teams at both the Smisa Stadium and Dens Park.

Amid the cup madness, a Tayside derby at between Dundee and St Johnstone at Dens has slipped under the radar this weekend.

I'll probably need to remind you all - and myself - throughout the day that it's a league game.

Dundee are currently in sixth spot and four places ahead of St Johnstone, but the points gap is just two points.

That means a win for the Perth side would move them all the way from 10th into the top half.

This league, honestly.

Image source, SNS

St Johnstone manager Craig Levein tells BBC Scotland: "This season has been crazy. Top six is the incentive for us. I heard the pitch wasn't in great condition, but it looks perfect.

"The more good players you have to choose from, the better your team should play - if the manager gets it right. I'm pleased to get some important players back, we've still got Dan Phillips to come back as well. He shouldn't be too long.

"Adama [Sidibeh's] story is interesting. He came over during the pandemic for a trial and everything then fell apart. He couldn't do anything, started playing football at a really low level - tier nine or 10 in England.

"He went up to tier three. He played in the top flight in Gambia when he was 19 or 20. He's no mug."

St Mirren manager Stephen Robinson tells BBC Sportsound: "It's a tough task ahead, but one we are very much up for."

"There is no bigger challenge. If you're going to win a cup, though, you're going to have to beat Celtic or Rangers at some stage.

"We will come out all guns blazing, we want to make it a really competitive cup tie. We've learned some lessons from before, we have to be right at the top of the game and start brightly."

On James Bolton's red card not being overturned, he added it is a "staggering decision".

"The people making these decisions, we have asked as a football club as to how they come to such a decision. I don't often say that much but this is staggering. At anything, at worst, it's a yellow."

Dundee manager Tony Docherty tells BBC Scotland: "I've rotated all the way through this period of games we've had where it's been really intense. We've had 11 games recently - nine away from home and the two home games were Celtic and Hearts.

"We need a freshness and intensity and that's reflected in the line-up. St Johnstone are in good form so it'll be difficult, but if we can get our ideas onto the pitch, hopefully we'll win the game.

"We take our form into context with the run of games that we've had. In the next 10 games, we have six at home. Our home performances have been outstanding but we haven't got the points our play has merited."

• Aberdeen
• Airdrieonians or Hearts
• Greenock Morton
• Hibernian
• Kilmarnock
• Livingston
• Rangers
• St Mirren or Celtic

Tony Docherty rings the changes after the midweek loss to St Mirren. Mo Sylla, Aaron Donnelly, Scott Tiffoney, Amadou Bakayoko and Zach Robinson all come in to the starting XI.

Owen Dodgson, Lee Ashcroft and Michael Mellon drop to the bench, with Malachi Boateng and Curtis Main out completely.

Not to be outdone, Craig Levein also changes five from the side that lost to Hearts through the week.

Kerr Smith and Adama Sidibeh make first St Johnstone starts, while Matt Smith, Liam Gordon and David Keltjens return.

Tony Gallacher, Ryan McGowan, Max Kucheriavyi and Connor Smith are among the subs, with young Fran Franczak completely rested.

Image source, SNS