Celtic have already seen some competitive action, Barcelona are further behind in their pre-season schedule. 

Does give Celtic the upper hand against an undercooked Barca? We'll see. If the Scottish champions were a steak they would have come out of kitchen medium. Barca are still rare.

In the International Champions Cup there is no such thing as a draw.

So if the game ends level after 90 minutes we go straight to penalties, with the winners awarded two points and the losers one.

Clear?

The man is headline news no matter where he goes or what he does. But Zlatan Ibrahimovic making his Manchester United debut in his homeland of Sweden means that he's even bigger business than usual.

He starts tonight. We've waited a long time to see him play in England. Can he still cut it?

Image source, Getty Images

Game on! Luis Suarez and Lionel Messi have the honour... but Celtic almost score inside 20 seconds! The Spanish champions sloppily hand over the ball, Patrick Roberts smashing an angled drive wide.

Lionel Messi and Abel Xavier. Lookalikey? We've never seen them in the same room.

Like your local bus service, we're running a couple of minutes late in Dublin. We haven't been stuck in traffic.

The newly-peroxide Lionel Messi leads Barcelona out of the Aviva tunnel. Scott Brown is alongside him. The only time the shaven-headed Celtic bruiser has used peroxide is to soften the boils on his feet.

Image source, Reuters

Are Lionel Messi and former Barcelona skipper Xavi both closet Celtic fans? Sounds like they are from the quotes attributed to the pair on the Scottish champions' website.

"They are a big club, with big fans, and I would like to see them qualify for the Champions League this year - it is where they belong,” gushs Messi.

And Xavi fawns even further. 

“I have always been outspoken about my affection for Celtic and I really hope this is the year they can make it back to the Champions League," says the Spain legend.

Quite the love affair. Don't be surprised to see Leo and Xavi in a pre-match boozer on Gallowgate when they next have a weekend off.

New Celtic signing Kolo Toure will not play today but could yet be drafted in for the second leg of their Champions League qualifier against Astana on Wednesday.

Celtic are short of cover in defence with Erik Sviatchenko, Jose Simunovic, Dedryck Boyata and Kristoffer Ajer all unavailable through injury.

Mikael Lustig was left out of the travelling squad heading to Ireland as a precaution, and Kieran Tierney might sit out at the Aviva Stadium after suffering cramp in Astana.

On top of Celtic's defensive absentees, midfielder Stefan Johansen has also been given the weekend off after his wife gave birth on Friday morning.

However, Simunovic is stepping up his recovery work after six months out with a knee injury.

Image source, PA

Celtic manager Brendan Rodgers talking to Sky Sports: "It is a test and an occasion. It is a good exercise and a real examination of the organisation and fitness of the team. Barcelona are missing a few but they still have got world class players. It will be a great experience for our players."

On facing Luis Suarez, who he managed at Liverpool: "I've told young Eoghan O'Connell to keep his legs closed if Luis is running towards him in the box!

"Luis is a magician and a wonderful player. He's world class, always finds space but for our young players it is an real examination of their defensive ability."

Half and half scarves are enough to send most football fans flying into a rage. So imagine how these easily-combustible people will react to this news...

Half and half SHIRTS have been spotted, external in Dublin. And these Celtic and Barcelona combos look horrendous. Like retina-burning horrendous. 

You might as well be wearing a fruit salad.

Image source, Daily Record

Image source, Getty Images

Bad news for tennis in Bolton? Perhaps.

German World Cup winner Bastian Schweinsteiger - new husband of Ana Ivanovic - looks like being one of nine players who may leave Manchester United.

The midfielder, who has announced his international retirement, trained on his own as United's full squad trained together for the first time this week.

Forwards Adnan Januzaj, Will Keane and James Wilson, midfielder Andreas Pereira and defenders Cameron Borthwick-Jackson, Tim Fosu-Mensah, Tyler Blackett and Paddy McNair are also reportedly set to be made available,, external though some may only leave on loan.

None of those players have been selected in a 23-man squad for today's friendly against Galatasaray in Gothenburg.

Jose's having a clearout.

You will notice there is no Bastian Schweinsteiger in that Man Utd squad...

Manchester United start with Sweden legend Zlatan Ibrahimovic at the apex of a very attacking front four. Will Jose Mourinho play like that in the Premier League?

One-time United target Wesley Sneijder starts for Galatasaray.

Let's find out what is happening over in Sweden. The team news is in. And Manchester United fans will catch a first glimpse of their big-name summer signing...

Image source, Getty Images

I wonder what Brendan Rodgers really thinks about this International Champions Cup lark. Not this PR-managed guff we always hear. He must be furious.

This 'glamour' friendly is the third pre-season game sandwiched slap bang in the middle of Celtic's attempt to reach the Champions League group stage. 

The Bhoys have played Saturday-Wednesday-Saturday since the first weekend in July - and even play Italian side Inter Milan in-between their opening Scottish Premiership games. 

Football has gone mad. Officially.

Champions League? Pah. Brendan Rodgers doesn't want to be embarrassed against the mighty Barca tonight. Only four changes from the side which drew at Astana on Wednesday.

A couple of interesting names in the Barca front three. Let's see how Efe Ambrose handles them...

Barcelona XI: Masip: Vidal, Camara, Mathieu, Roberto; Martinez, Denis Suarez, Arda Turan; Luis Suarez, Munir, Messi.

Celtic XI: Gordon; Janko, Ambrose, O’Connell, Izaguirre; Brown, Bitton, McGregor; Roberts, Griffiths, Forrest.  

Aaron Ramsey was at it, Fabio Borini is at it, even Lionel Messi is at it.

Disturbing reports that presumed no-nonsense Bournemouth centre-half Steve Cook has even joined the blond/silver crew.

Image source, Reuters

But have you ever copied a questionable footballing hair cut? Were you sent home from school? Banned from work?

Told off by your mum?

Image source, Getty Images

Let us know what you did to your head and why. Even better, send us a picture.

You can get us at #bbcfootball. Fire away!