Charlie Adam and Leigh Griffiths have been recalled to the 26-man squad along with debutants Scott Bain and Mark Reynolds for a friendly against Qatar at Easter Road on June 5 before their crucial Group D qualifier in Dublin eight days later live on Sky Sports.
Strachan has been largely consistent when picking his squads and starting line-ups but says players always have the opportunity to impress and break into the side.
He said: “I think if you remember back to when Barry Bannan was on holiday two years ago and we called him in, he’s trained and said to us ‘he needs to play’ and he’s played against Croatia. I think we set the precedent that day.
“Players can impress at training. Charlie and Leigh have been here before and they’ve had games before and if I felt as though they didn’t have a genuine chance to play I would’ve brought in younger guys to fill some spaces. They’ve forced their way into the squad.
“It’s consistent the squad – it doesn’t change much – that’s because players who have played and been involved in the squad make sure they are picked again the next time. They decide if I’m going to pick them with their attitude. It’s not just the ones that play, it is the ones that don’t play.
“They all seem to get on well together and they all seem to want to win. And that’s all I ask of anyone who joins this squad. You come in this squad and you make sure the squad is bigger than you, that’s all we ask.”
Bain’s first call up to the national side caps off a stellar season in the Scottish Premiership where he has helped Dundee to a top-six finish.
Strachan said goalkeeping coach Jim Stewart had been keeping an eye on Bain, who has been called up to replace Hull’s Allan McGregor and Burnley’s Matt Gilks who are struggling with injuries.
He said: “It was a bit of my thinking, but mostly Jim’s thinking. Obviously Allan McGregor has got a problem which we’ve known for about a year. He’s been carrying an injury for about a year and he’s been playing with an injury for his club.
“I think the club and himself need time for that to calm down and he’s been brilliant for us so we can only respect his decision that he needs to get that sorted out and it’ll be a benefit for Hull and it’ll be a benefit for us in the long term.
“So young Scott is going to come in and he’s been playing well this year. Jim has been impressed with him and he believes he’s a player for the future, but it’s not only the future – it’s now.
“He’ll be working with two excellent goalkeepers and that will benefit him and the enthusiasm of Scott I’m sure will benefit the other two goalkeepers.
“The three that we’ve had have been brilliant and they have made my life hard at times, that’s for sure. And Gilksy has backed them up nicely – he’s got a problem and that needs to be dealt with so then we have to look about and we think Scott is the best choice just now.”
Charlie Adam returns to the squad after impressive displays for Stoke which included that spectacular goal against Chelsea at Stamford Bridge.
Strachan said: “We’ve seen Charlie Adam recently, we’ve all seen the wonder goal but there is more to it than that. There’s been a consistency to Charlie’s performances and he’s found a position at Stoke which suits him and that suits Stoke the way they are playing at the moment so it has been a good two months for Charlie, that’s for sure.”
Celtic’s Charlie Mulgrew is also named in the squad after coming back from injury to make his first appearance in five months against St Johnstone at the weekend.
The Scotland boss also welcomes back Mulgrew’s team mate Griffiths into the mix for the two games and said it was important to strike a balance between players who may need a rest after a long season, and others who need games before the crucial Group D qualifier in Dublin.
“He’ll (Griffiths) be fresh because he didn’t play too many games at the beginning of the season, a lot of substitute appearances. So he’ll be fresh and you need to take that into consideration at this time of the year; who is fresh? Who needs games?
“We’re not a squad that everyone is playing up until the end. We are not playing in Champions League finals, European finals or FA Cup finals, big games like that.
“A lot of the squad have had a break but the ones who are playing in the play-offs, like the Norwich guys, we have to take that into consideration.
“That’s why this game against Qatar will be great – we need extra games for people like Charlie Mulgrew and the lads like Matt Ritchie who stopped about May 3, I think, so it is imperative they get games.
“But the training will involve a lot of games. Usually it is something else we do, it’s movement and shape, and to bring the boys up to speed we’ll have to do more contact training to bring them up to speed with games.
“He’s (Mulgrew) back in the Celtic side and I don’t think they’d put him in if he wasn’t ready, especially at this stage of the year. I think they are trying to give him a couple of games and I think they are hoping that we are going to play him as well so he gets games in.
“Charlie was a huge asset for us when we played the Republic last time – and I mean huge – I thought he had a terrific game and having Charlie in the squad makes us stronger – not only midfield but other positions.”
And Strachan is hopeful that the friendly against Qatar will provide his players with the ideal preparation before they travel to Dublin.
The Scotland manager is also keen for locals to head along to Easter Road to support the side.
He said: “I think it’ll be good for everybody. I’ve seen them (Qatar) on video a couple of times, I haven’t seen them live and I’m really looking forward to it. I hope the weather is a wee bit better than it is today so we get a great crowd.
“It’s a great chance for the youngsters in this area and people who couldn’t get across to Hampden, Ibrox or Celtic Park in the past year to see the team playing. It’ll be a good opportunity for them to come along with their kids and families to see the game.
“But the most important thing for us is we’re glad Qatar has agreed to play us because we need games at this time of year for certain players.
“I’ll hopefully have a full squad to choose from as well. I didn’t expect a full squad as I asked some of the players if they needed a rest and they said no.”
Watch Scotland take on the Republic of Ireland live on Sky Sports 1 HD on June 13 from 4pm.