IT would be entirely forgivable if the Celtic contingent in the Scotland squad was feeling slightly jaded when preparations for the Russia 2018 qualifier with England get underway at Oriam around this time next week.

The season the Parkhead club – who have had Stuart Armstrong, Scott Brown, James Forrest, Craig Gordon, Leigh Griffiths and Kieran Tierney called up – has had has certainly been enjoyable for the players involved.

But qualifying for the Champions League group stages, winning the Betfred Cup, going undefeated in the Ladbrokes Premiership and reaching the William Hill Scottish Cup final during these last 10 months has certainly taken it out of those involved.

Read more: Gordon Strachan: Celtic's Callum McGregor unfortunate to miss out on Scotland bowThe Herald: 21/05/17 LADBROKES PREMIERSHIP. CELTIC v HEARTS (2-0). CELTIC PARK - GLASGOW. Celtic's Leigh Griffiths celebrates opening the scoring.

Will they be able to raise themselves one last time against Gareth Southgate’s side before heading off for a much-needed and well-earned break? Fatigue has to be a concern after such a momentous campaign.

Especially when you consider that all six of those aforementioned players started in the last Group F match against Slovenia at Hampden back in March and are strong contenders to do so again on Saturday week.

Gordon Strachan appreciates, having spent four memorable years as manager of Celtic himself, just how demanding it can be at the Glasgow outfit.

He is, though, hopeful they will be able to transfer the success they have experienced at club level to the international stage and help their country record a famous victory over the “Auld Enemy”.

“There was a concern there might be a dip after the Celtic players won the league, but there wasn’t a dip there,” he said. “They have got that winning mentality it seems. They say: ‘I’m enjoying this, I must keep this going, whenever I play I must win’.

“There are so many clubs who win things early then drop away. We have seen that many times. Indeed, my son’s team, Doncaster, won the league with five to go and then had two draws and three defeats after that. It is very hard to keep your team going.

“But they have kept it going, the whole Celtic gang. We saw how they played here against Slovenia and we’re hoping they can keep that going.

“They’re on this run where they think they are invincible which is fantastic. They are enjoying every game. Ask any of them if they’re tired just now. Tiredness only seems to creep in when you are getting beat.

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“They will be fine. There is an excitement factor about this game. Some of the games you play in the summer don’t have the thrill factor. The thrill factor is there with this one.

“We know what we are going to get from the players. They are a group I trust absolutely. When you play in big games you have to play players you could trust. It’s starting to get exciting.”

Strachan was responsible for some notable achievements during his own tenure as Celtic manager. He became the first man since Jock Stein to lead the Parkhead club to three consecutive Scottish titles. He also guided them through to the knockout stages of the Champions League twice.

He knows the magnitude of what Brendan Rodgers’s men did on Sunday – they became the first top flight club in 119 years to go the entire league season unbeaten – and have the chance to do on Saturday – they will win the treble and go the entire domestic campaign undefeated if they can beat Aberdeen in the William Hill Scottish Cup final at Hampden.

“It’s sensational,” he said. “Not to make a mistake or have a lapse in concentration during the season is incredible. I’ve been there. When I was there, we had lack of concentration a couple of times. So to do that has been absolutely sensational.”

Brown, who is poised to captain Scotland against England, has been transformed since getting an extended break from football last summer and has been absolutely crucial to Celtic’s success in recent months.

Strachan, who has been something of a mentor to the central midfielder since signing him from Hibs for £4.4 million back in 2007, has been delighted by his resurgence and knows the national team will benefit from his presence hugely next week.

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“His mindset from a year ago is completely different,” he said. “People were saying ‘is he past his best?’ and ‘is he as fit as he was?’ He had to deal with that.

“But all the Celtic players are much fitter than they were last year so that makes you mentally stronger. And when you’re mentally stronger, you start winning games. It just keeps turning over.

“He’s far more influential now than he was 10 years ago. He had influential spells 10 years ago when they were so exciting it was untrue. But he has an influence for 90 minutes now, longer.”

One player who is in no danger of experiencing burnout is Griffiths who has, despite scoring 40 goals in all competitions for Celtic last season been second choice striker behind Moussa Dembele this term.

He has netted four goals in his last five games since Dembele got injured, but Strachan revealed he would have had no qualms about pitching in the forward, who missed an open goal in the Slovenia game, if he had still been warming the bench.

“He didn’t have much football before we played Slovenia and I thought he was terrific,” he said. “I thought his 45 minutes was absolutely terrific for somebody that’s not played. You can see that he’s kept himself sharp, hungry, wanting to play and to prove himself.”

Yet, Strachan, whose side lost 3-0 against England at Wembley in November despite performing well, knows the visitors will have a few dangerous players up front themselves and will be desperate to win a game that will take them closer to competing in the World Cup finals.

“They’ll want the game,” he said. “Harry Kane has scored eight goals in three games and he is still driving away. Coming up to Scotland isn’t a big deal for these guys. They’ll relish it.”