Scotland manager Gordon Strachan has named Scott Brown as his first captain.

Celtic skipper Brown will lead out the team for the first time ahead of tomorrow night's friendly against Estonia at Pittodrie.

"He already knows what it's like to be a captain with pressure and that made him favourite," Strachan told a press conference in Aberdeen.

Gary Caldwell and Kenny Miller have shared captaincy duties in the absence of Darren Fletcher, who is battling a chronic bowel condition.

But Caldwell has returned to Wigan with an injury and 33-year-old Miller is unlikely to start as the Vancouver Whitecaps striker is in the midst of his close season.

Strachan confirmed Caldwell's withdrawal was one of several from his squad, adding: "He's left. Grant (Hanley) has left too, they did well to come up, they'd really been struggling.

"Ross McCormack has left, he's got some sort of bug but he made it up here which was terrific.

"Young James (Forrest) went back because I felt it might be too much to play two games back to back for him. So he's away to Celtic and they'll look after him there."

The Scotland boss is more than willing to co-operate with Clydesdale Bank Premier League managers as all parties aim to minimise player fatigue.

"I spoke to a lot of managers recently and I'm trying to do the best for the group and the best for the managers," he added. "The team that is picked is the best one we can put out tomorrow.

"We're taking into consideration the last time they played, the conditions they played in and who'll be playing at the weekend.

"We'll try to help them and try to get something positive for ourselves."

Strachan is preparing to make his debut as Scotland manager at the ground where he spent seven successful years as a player between 1977 and 1984.

He added: "When I first got the job I thought 'wherever the first game is, it will be fantastic' but I think I've realised it's even more special that I'm going back to Aberdeen where I enjoyed smashing times with great players.

"I'm going back again 30-odd years later and the best wishes have been overwhelming, especially in Aberdeen. The people that I've met around this area recently have made it even more special.

"The group Craig (Levein) passed to me are a smashing bunch of players and sometimes they're over enthusiastic but we can always curtail that."

Strachan told Brown he would be leading the team out five minutes before the captain's press conference this afternoon.

The 27-year-old, who will win his 30th cap tomorrow, said: "It's a huge honour, a thing you dream of when you're younger, captaining Scotland.

"I've been lucky enough to do it for Celtic for the last couple of seasons and now to get the chance for this game for Scotland is a great honour."

Ross McCormack, the former Rangers and Motherwell forward, was the first of the 28 squad playersrs to withdraw. Leeds revealed he had then been sent home with "flu symptoms".

McCormack wrote on his Twitter account: "Gutted to be pulling out the Scotland squad ill... Now just rest and get fluids in me and be ready for wolves on Saturday!!"

The 26-year-old, who scored in a 3-1 friendly win over Australia in August, was recalled to the squad by Gordon Strachan days after netting in an FA Cup victory over Tottenham.

Meanwhile, Scotland manager Gordon Strachan cast aside the old football adage of taking 'one game at a time' as he used his first two international training sessions to prepare his team for his World Cup "gamble".

Strachan was looking beyond tomorrow night's Pittodrie friendly against Estonia as he furnished the players with information on how he wants them to play.

A session that incorporated some Aberdeen youth team players allowed him to put across his ideas ahead of next month's double header against Wales at Hampden and Serbia in Novi Sad.

Scotland look set to adopt a more aggressive pressing game under Strachan, who has been working on at least one system involving two strikers, a formation predecessor Craig Levein rarely used.

And the former Aberdeen midfielder revealed the Dons Under-19s were crucial help with his tactical preparation.

"They allowed us to do things we couldn't do in that space of time you have got for training," Strachan said at a press conference this afternoon.

"I said to the guys it was invaluable, your help, because you can't normally do this at international level, work with defenders and midfielders and attackers.

"The Aberdeen lads allowed us to split up and probably do two days in one.

"So far we have been working towards what we may face in the near future, looking at a couple of systems.

"And the Estonia game, the thinking has to start now. That's no disrespect to Estonia, I'm sure they will understand that we're building for later games.

"We have had to do a lot of talking about what might happen in the future."

Strachan will use the 90 minutes to gear up for Wales on March 22 but he admits his team selection may be guided by the heavy Pittodrie pitch.

James Forrest has already been sent home for that reason after making his comeback form a hamstring injury during Celtic's William Hill Scottish Cup win against Raith on a boggy Stark's Park surface.

Strachan, who has also lost defenders Gary Caldwell and Grant Hanley to injury, and forward Ross McCormack to illness, added: "I have said we are at the stage where we have to gamble anyway.

"What we have to take into consideration is the type of pitch we play on, which might be beneficial later on if we come up against a similar surface.

"What we are trying to do is find a system or maybe two systems that suit most of our squad, and possibly even a third, but that would be dependent on the players we have.

"I want a win and a performance and players who feel good about themselves when they go back to their clubs."

With Scotland bottom of their World Cup qualifying group with two points from four games, Strachan hinted he was looking at ways of employing two forwards.

"Whatever happens when you play two strikers, you have to make sure you have enough in midfield that you don't leave gaps," he said.

"You have to make that compact. Liverpool are playing with two, one up front, Suarez just off him, a wide man and a narrow midfielder on the other side. So that's different.

"You can play two up front with a diamond in midfield. There are lots of different ways of playing 4-4-2.

"Liverpool's shape now is determined by their great players, Manchester United's the same.

"You can play two but you have to make sure your midfield is able and ready to carry the two and if they play with two strikers, they need to know how to help us defensively as well.

"So it's one or two things we have worked on this morning."

Scott Brown, who will captain Scotland tomorrow, revealed they would be looking to get on the front foot in an apparent break from Levein's tactics.

"We are going to try to press them high up the park and put teams under pressure," the Celtic midfielder said. "It's a wee bit different to what we used to do but it's looking exciting so far.

"I wouldn't say a lot has changed but he (Strachan) is trying to get his own way to play in each formation and showing us bits and bobs on DVD as well. It's looking good.

"The manager is happy to let us go out and play and show that we can take on players and create chances. We have been unlucky in the past, especially at Hampden, we have created a lot of chances and just didn't finish them. Now it's a fresh start and we are looking forward to it.

"We have sat back and let defenders come towards us, but hope we can press them high up the park and make them make mistakes.

"There have been all different ways we have played and different formations. Some have worked and some haven't. We will see if this one works and hopefully it does."