Robbie Muirhead is showing an admirable level of enthusiasm, skill and aggression to trouble the visitors' defence. For Celtic, poor Jason Denayer's head will be birlin' as, first, he is lobbed in the box by young Muirhead and, as the ball rolls out of the Celtic penalty box, the Belgian takes a thumping shot to the temple. Ouch.

Radoslaw Cierzniak slides to his left to turn Kris Commons' deflected shot round the post for a Celtic corner, John Souttar doing enough to take the sting out of the Celtic attacker's dig at goal. United defend stoutly from the corner and in the next move the United keeper gratefully clutches a snap side-footed shot by Virgil van Dijk. It's a decent game, this.

Jamie McGilchrist: "Muirhead already putting himself about more than Ciftci. Telfer is a talent. How long before Celtic come snooping? #bbcscotfootball"

Van Coupon: "Has Scott Brown forgotten how to win a tackle #bbcscotfootball"

Celtic keeper Craig Gordon arches his back like a gymnast on the high beam and throws up an arm to turn over Robbie Muirhead's sizzling left-foot shot from 20 yards.

United's Charlie Telfer swings in a cross from the right but it lands over the head of his team-mate in the six-yard box. Moments later Ryan McGowan sends a glancing header just wide of Craig Gordon's goal from a corner kick.

Image source, SNS

The Dundee United fans have given former midfield favourite Stuart Armstrong a warm reception as he returns to Tannadice in Celtic colours.

Virgil van Dijk makes a run to meet a corner from the left but, despite being almost unchallenged, his body position is off and he heads over the United bar.

Celtic full-back Emilio Izaguirre takes a knock on his ankle, I think, at the edge of the box and has to wait for play to stop before he receives treatment.

United's sole striker Robbie Muirhead pounces on a moment's hesitation by centre-half Virgil van Dijk and nods the ball ahead of the Dutchman but such is the Celtic player's pace and strength that he recovers in time to regain possession and roll the ball back to keeper Craig Gordon.

The rampaging Honduran Emilio Izaguirre sprints into an advanced position and pings a cross from the left right across the face of the Terrors' goal, but Stefan Johansen is unable to connect.

United's Chris Erskine floats a left-footed free-kick into the back post area from out on the right and Callum Morris heads wide...after fouling.

BBC Scotland football pundit Willie Miller

"It looks like Celtic are going to see a lot of the ball. Dundee United are retreating. It looks as though United are trying to frustrate Celtic."

It's a brisk pace in the early moments, Celtic pressing.

And we're under way at Tannadice.

Grant Campbell on Facebook: "Hopeful but realistically doubt it. Head says 3-0 Celtic, heart says 2-1 Dundee Utd or a draw."

The teams are out on the pitch; we're heading for kick-off.

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United are in fifth place in the Premiership table. They have struggled since losing Gary Mackay-Steven and Stuart Armstrong to Celtic but need to find form very soon to catch third-placed Caley Thistle and St Johnstone who are six points and two points ahead respectively. Inverness have played one game more than Jackie McNamara's side while the Perth Saints have played two games more than United.

Dundee United manager Jackie McNamara

"We hope to pass the ball better than we have been. It's important we do things we're good at. We have a young team, with four teenagers starting and more on the bench. It's imperative that we pass the ball. We have five players out so it gives the younger ones a chance. Robbie Muirhead has the ability to cause defences problems. I don't think there will be many surprises with both teams. Maybe it's a measure of success if we are meeting them seven times in a season. Credit to St Johnstone - they had a great result yesterday. We have games in our own hands to close the gap (on Inverness and St Johnstone)."

BBC Scotland football pundit Pat Bonner

(On Celtic in Scottish Cup semi-final) "I must say the defending was very poor. You would expect Virgil van Dijk to head the ball away and for defenders to deal with balls into the box. They got done on the counter attack. You would expect better. We have seen it in Europe - they don't play with a plan B. Yes, they will win the league but they should be now thinking of the close season, pre-season and into the Champions League. Could that group of players defend for 70-80 minutes there? Europe is too important."