For Celtic fans, Scotland’s emphatic 4-0 win over Albania was a rather familiar sight. Whether it was the striking shots of James Forrest’s brace, Ryan Christie’s never-ending enthusiasm in the final third or Callum McGregor’s string pulling in the middle of the pitch: Alex McLeish’s squad had a certain green and white glow about it.

Even before a ball was kicked, the nation let out a collective grumble when Kieran Tierney ruled himself out of the game in the eleventh hour. Indeed, many feared Scotland would struggle without one key Celtic star, but ultimately welcomed a joyous surprise thanks to three more from Brendan Rodgers’ dynamic and somewhat new-look midfield.

And while a number of players from all over the British Isles (and even further than that) came together to save McLeish in what seemed like his darkest hour as Scotland manager, there seems to be very little doubt that this current national side are now firmly built on Celtic foundations.

It would be foolish to start anywhere besides the seemingly evergreen form of Forrest. Once considered an injury-prone winger with no more than a few tricks in his locker, the 27-year old has morphed into a huge player for Celtic under Rodgers’ tutelage and Scotland seem to be finally reaping the fruits of Lennoxtown’s labour.

Although Forrest’s assists per 90 minutes over the past five years haven’t shifts too dramatically from an average of around 0.24, his goalscoring has drastically improved under Rodgers. In the 2015/16 season the winger averaged 0.09 goals per 90 minutes, yet that figure has increased each season since and currently stands at 0.48 goals per 90 minutes in this current campaign. Which isn’t too surprising when we consider just how well the wide forward took both goals on Saturday night.

Christie is another example of this Celtic effect. Although the Inverness-born talent hasn’t shown his worth over anywhere near the same time period as Forrest, he has displayed a sudden and drastic upturn in form since he earned the trust of Rodgers and Celtic’s wider squad.

While Christie is primarily an attacking player, his key asset to Celtic (and Scotland) is his boundless energy and the way he closes down opposing players with such speed and tenacity. Indeed, the midfielder is currently averaging 8.3 defensive actions and 4.94 interceptions per game this season, which is far more than he did for Derek McInnes’ Aberdeen side last season. And was evident in Scotland’s first goal in Albania.

McGregor is another, proud graduate from the Rodgers school of midfield mastery, but while his talents are clear for all to see, his most direct contribution to Scotland has been the manner in which he has slotted in to the holding midfield position once occupied by Scott Brown. For many, John McGinn or perhaps even Kevin McDonald were the go-to replacements for the former Scotland captain, yet McGregor was Rodgers’ hand-picked solution to Brown’s injury problems at Celtic Park and McLeish has clearly taken note of the young midfielder’s success at the base of midfield and applied it to his own squad.

Saturday’s win over Albania was first and foremost a superb, counter-attacking display and that was largely down to the manner in which McGregor could quickly move the ball from defence to the final third. As Celtic have seen their form improve with clearer, attacking displays since the 25-year-old slotted in to the playmaking role, so too did Scotland see a notable shift in speed and precision going forward when McLeish followed suit.

To a lesser extent, Celtic also deserve a fair amount of credit for Armstrong’s contributions to this current squad. Although the midfielder has since moved on to pastures new, he hasn’t exactly done enough at Southampton this season to suggest his form is in any way a result of his new surroundings. And there’s a very obvious connection that still remains between the way he plays his game and how the likes of McGregor and Forrest are able to play off him in the middle of the park.

Add to that the imminent return of Tierney and the long-term return of Leigh Griffiths up front and it’s clear to see that McLeish’s squad largely picks itself as long as his Celtic contingent continue scoring goals and winning games in the Scottish Premiership. And for an international manager, that degree of chemistry and certainty is hugely valuable and could mean the difference between finishing third or fourth in a qualification campaign with a makeshift team of mercenaries and sitting first or second with a side that play like coherent, domestic champions.