Alan Stubbs watched on as Virgil van Dijk tore up the Scottish Premiership with Celtic from 2013 to 2015.

Now he's getting a touch of deja vu with current Hoops defender Cameron Carter-Vickers.

The Scouser charted the Dutchman's progress from Glasgow to Southampton and then on to Merseyside where he soon became arguably the best defender in the world while playing for Liverpool.

That pained Stubbs greatly considering he is a dyed-in-the-wool Evertonian. However, the former Parkhead defender admits that he's getting a similar feeling watching Carter-Vickers as he continues to impress for Ange Postecoglou's side.

He is not nicknamed 'The Fridge' for anything, as Stubbs will attest. Carter-Vickers is cool, calm, and collected. He is generally unruffled, unflappable and unfazed by anything. He has also never lost a league game when partnered with Swedish centre-back Carl Starfelt.

"He can certainly play," Stubbs told The Celtic Way. "I remember seeing him at Tottenham before he left and I thought he possessed very good attributes.

"I wondered why he wasn't getting more regular football. Ever since he has gone to Celtic he has played more regularly and, in my opinion, alongside Callum McGregor hei is the first name on the teamsheet every week.

"He has gone from strength to strength, he has grown in confidence and he is quick - which I didn't think he was. He is great in the air, he is comfortable with the ball. He ticks all the right boxes. Carter-Vickers has to take a lot of credit for that himself.

READ MORE: 'Ange who?' - Alan Stubbs on the striking Celtic parallels 24 years apart

"The last Celtic defender to make it all look so easy was Virgil van Dijk - and he has been lauded as one of the best defenders in the world recently. It is OK to the naked eye for people looking on to think the game is easy, but we all know it is not.

"Defending is an art form. There are players out there who can make defending appear to be very difficult and then there are players like van Dijk and Carter-Vickers who make it look easy. They do that by performing the hardest tasks with the minimum of fuss. Van Dijk was one of them and Carter-Vickers is slowly but surely following in his footsteps.

"So there is an art in defending but also one in how not to defend. I have to admit that both Van Dijk and Carter-Vickers are role models of consistency and if I was talking to other players about defending I would tell them to study these two guys in particular at this moment in time. They are both fantastic examples of how defenders should operate at the top level."

Celtic Way:

A recently-revealed statistic from StatsBomb showed that Carter-Vickers has only lost one aerial duel in a league match since Christmas Eve last year. The American has won a staggering 34 out of 35 contested with only Kilmarnock striker Kyle Vassell able to win a header against him.

Stubbs, who led Hibs to Scottish Cup glory in 2016, was particularly impressed by the data from January's Glasgow Derby, when Carter-Vickers won eight out of eight headers despite being up against the robust and aggressive physical presence of Alfredo Morelos.

"That's an impressive statistic," he continued. "I'm thinking especially in the modern day when you look at the fact that players are predominantly bigger now and more athletic.

"I have to be honest, I prided myself in being a good defender but that's an amazing run of winning headers. He's not the tallest either which makes it even more impressive as he is about average height for a centre-back.

"He has either a perfect spring or his timing is excellent - or both of those abilities. It is OK to be able to jump and win a header but you've also got to know when to jump. A lot of the time if you are not in position then you are chasing the game.

"A defender being in the proper position does not happen by accident. It is all about getting distances right in terms of goal-kicks, throw-ins and set-pieces so he is clearly putting himself in the right areas which is a very good habit to be in as a defender.

"I mean how can you win eight out of eight headers against a team with Alfredo Morelos? Cameron would have been up against Morelos in that New Year derby at Ibrox and the guy is a pest, he would have been in his face trying to make life awkward for him.

"He would have been trying to put him off for sure - and that is another element in the equation. A lot of strikers are not interested in actually heading the ball but they will try to put you off your game by giving you little nudges here and there.

"It is harder to cope with that than some people make it out to be. Imagine if you are looking at the ball and trying to get your timing right and a player like Morelos gives you the slightest nudge and that knocks your timing. It can have a big effect."

Celtic Way:

Stubbs also drew attitude comparisons with two former American internationals - Tim Howard and Brian McBride - as well as Australian midfielder Tim Cahill who were all team-mates of his at Goodison Park.

"There are players from certain countries whose attitude and mentality is very different to others," Stubbs said. "I was team-mates with Tim Howard and Brian McBride who played for the USA national team. Tim Cahill, who was Australian, falls into this category too.

"They were all focused and very driven. Their attitude was spot-on. All three of them were very career driven and they were mentally strong; they had a different focus in terms of winning.

"That rubbed off on the rest of the Everton players in that dressing room. I can imagine Carter-Vickers being exactly the same in the Celtic dressing room."

A hybrid of Howard, a clone of Cahill and a model of McBride. There is only one Carter-Vickers though.

He may well never scale the dizzy heights of Van Dijk in being crowned the best defender in the world but Carter-Vickers is certainly on the right career trajectory in the green and white of Celtic