IT was Sir Matt Busby who first coined the phrase “if they are good enough, they are old enough” and the great man certainly followed through on his words.

Gordon Strachan doesn’t have a teenage George Best to pick from or a Duncan Edwards, mores the pity, but the Scotland manager has shown so far that he is more than willing to offer a chance to any players he believes can help out the international team.

He cares little for age. It is why Kieran Tierney became at 18 years and 297 days the ninth youngest to ever wear the Scotland shirt. It is why Oliver Burke was given his debut who is not much older, and this was before he became a superstar.

John McGinn of Hibernian is 21 and plays in the Championship. He was named in the squad for what is lining up to be two massive World Cup qualifying games against Lithuania at home a week on Saturday and then the tricky away trip to Slovakia.

Rangers’ Barrie McKay, another 21-year-old, has been called up, as has Jack Hamilton the Hearts goalkeeper who is 22.

Under previous managers, there was no way so many young and relatively inexperienced players would be in the same squad. They won’t all play, only Tierney and Burke of any chance of a start; however, the manager has made it clear that if he thinks a player can be an improvement then he’ll be in.

The message to anyone out there with hopes of becoming a Scotland player is this. Do well and you’ve a chance. It’s really that simple.

Strachan said: “It was disappointing Kieran had to pull out of the last squad, but he had to go away and get an injection in his ankle. But he turned up and was devastated not to be a part of the squad.

“So he’s 19, let’s go. Let’s get him in. It is there for you if you want to take it on. But it doesn’t stop the door to Gordon Greer. If somebody is better than Gordon Greer then get yourself in.

“In my opinion, there is nobody better than the four centre-halves we have got now. I think they are the best for our squad and what we have got at the moment. If somebody wants to do better then get better and play for top clubs.”

Strachan is not interested in bedding a player in at Under-21 level and then seeing how he does at that level. Oliver Burke, the record £13m man who is plying his trade with RB Leipzig is the prime example.

Strachan would rather see how a teenager copes with training with the senior squad, rather than have him working with another group, if he sees there is something about the player he likes.

The manager said: “You have to deal with that pressure. I think that expectation of a young player is something you have to deal with. If you can, you get on and you become a better player.

“It has happened to all of the top players you have known who have come into the Scotland team or the England team.

"Oliver has put himself there because he has done well. I saw him at Charlton when nobody knew about him.

“I went to see Tony Watt and he came on as a sub. I was going to pick him.

"That is what I have said to Scot Gemmill, bypass it. You can’t say ‘oh, he should’ve been in 19s, he should’ve been in this’. No, no, no, he is coming with me.

"If people can do that there is an opportunity for you. If you are going to blow us away we are not going to mess about with 19s and 21s and all the rest of it. Bang, you are up there, in there. There are so many good players who started at an early age.”

And talking about giving the young ones a chance, Shaun Maloney is back in the squad at the age of 33 after missing out last time.

Strachan loves the wee man, the two did enjoy great times together at Celtic, and believes the likes of Tierney and McKay will learn so much from watching and learning from a player who is well known to be still the best in training every time the squad gets together.

Strachan said: “Shaun has been doing his stuff as a substitute. He played last week and was terrific. It might be we need his experience coming on at certain points. His body seems to be used to that at the moment.

“But I’ve got to say I am still convinced that the best training any of the youngsters we’ve had in recent months, and the best education as well, is watching good professionals doing their stuff.

“Maloney, Darren Fletcher, James Morrison and James McArthur are there. If they watch these players and take in what they’re doing on and off the park, you cannot help but get better.”