TRUE story about Johan Mjallby. It’s the summer of 2000, Celtic have just appointed Martin O’Neill, and having landed at Glasgow airport after a mini-tour of Ireland, Denmark and Luxembourg, players and media alike are lined up waiting on taxis.

It’s late. A man is driving one of those road sweepers right at the kerb where, if he had looked up, a couple of famous, but tired, faces were standing.

This guy’s bad luck was that he swept past Mjallby, his sweepers hit a puddle and Celtic’s giant Swede was splashed.

Mjallby then punched the van and, for a second, this writer honestly thought it was going to topple over, such was the power of the hit.

What the press pack learned that night was never to annoy anyone, especially not Mjallby, when driving a vehicle that has a top speed of 3mph. Getting away is difficult.

For such a nice bloke off the field, Mjallby wasn’t one to mess with on it. A powerful defender who once

tackled a Bordeaux player with his groin, this man-mountain could play a bit as well.

All Celtic supporters who saw him in his prime would have at one time wished that their second favourite Swede was still about.

So, who better a judge than he when asked about a current centre-half who – and I may be wrong – has never swung a punch at a moving vehicle?

Kristoffer Ajer in recent months has emerged as a superb centre-half. He wins high balls,can put a tackle in and loves breaking forward with the ball, head up,looking to make a pass.

And to be mentioned in the same breath as the best defender in world football is a decent compliment.

“Ajer is still very young, he is 20, but he’s got all the attributes to become very good,” said Mjallby.

“Remember, Virgil van Dijk was probably further ahead when we brought him in but when you see him playing for Liverpool now with all his leadership qualities, it took him a while, not football wise, because he was too good even when he first

came here.

“It was more a case of telling him to stay focused because it was too easy for him. It took him a while to get his leadership qualities out. He was new into the club and the atmosphere of everything surrounding Celtic

football club.

“It’s important for Kristoff as he’s so young to improve his leadership qualities before he’s contemplating going to another league.

“He could definitely follow the same path as van Dijk if he stays. He’s got every chance.

‘I’ve actually been waiting on him to a certain degree. He caught my eye when he started to play. Now he’s got more experience and he’s probably maturing a lot as well.

“He’s got every chance of becoming a very good defender.

“Next season the path will be clearer for him. It’s a great chance for him to improve. He’ll have more playing time to put his stamp on the way he wants to play.

“You would assume that he’ll need an older head there beside him,

especially in high-pressure games.

“But he’s got every chance. I just want to see him play even more games in the centre of defence

week in, week out before he decides to move.”

A bonus for Ajer is that with the Norway team, he is being coached by Lars Lagerback, who made Mjallby captain of Sweden.

“That helps because he’s got a good teacher there defensively in Lars Lagerback who we used to have in Sweden,” said the former Celtic man.

“Lars knows all about defending… maybe not going forward!

“So he’ll be a good teacher for him. The fact he plays him regularly shows Lars thinks he’s a good defender and that he’s doing the right things.”

From the young to the old(er) now, and Mjallby would like to see Mikael Lustig stay for one more season.

Should Neil Lennon get the job then Lustig, 32, will be offered another 12 months and Mjallby would like to see his countryman kept on. “I love Mikael as a player and a person. He’s been a fantastic servant for Celtic football club,” he said.

“Sure, it depends what the club wants and what Mikael wants.

Whatever they choose to do, I think you can always rely on Mikael.

“Obviously, he is injury prone. He’s getting older. So you need back-up if you are going to keep hold of him.

“Whatever happens I think he’s been a great servant not only on the pitch, he’s great in the dressing room with the lads and popular as well.

He maybe doesn’t have the star qualities the way he plays the game. But everyone really respects him for what he stands for.”