Steve McClaren has warned his high-flying England players that no-one is guaranteed a place in his team.
McClaren is determined to create a competitive atmosphere inside the camp after enjoying a five-star start to his Euro 2008 campaign.
England shot to the top of Group E after hammering little Andorra 5-0 at Old Trafford without five regular first-teamers.
Michael Owen, Rio Ferdinand, Gary Neville and Joe Cole were all missing through injury and Wayne Rooney was banned.
The new boss stressed that no-one can expect to walk straight back into the team - and no-one can assume they will stay in.
McClaren said: 'Nobody is a permanent fixture and no-one can count on having a shirt all the time.
'They have to work hard for their clubs in between and show form and then, when they come to England, they have to perform well for the team.
'They must be available when they are asked to make an impact, which the subs have done.
'We're building a squad and I've said to these players they are in the squad at the moment but it's up to them whether they stay in or not.'
Only Ferdinand, who missed the Andorra game with a toe injury, has a chance of returning in time for Wednesday's game in Macedonia.
Rooney serves the second game of his two-match ban and will be available for the home game against Macedonia on October 7.
Strikers Peter Crouch and Jermain Defoe each scored twice against Andorra and Andrew Johnson impressed McClaren when he came on as a substitute for the last 20 minutes.
It is implausible McClaren will keep Rooney on the sidelines simply because Defoe and Crouch cashed in against one of the world's worst teams.
The Manchester United striker will return to the starting line-up as soon as he is able but the manager is anxious not to puncture the confidence of Crouch and Defoe.
Crouch's double against Andorra took his international tally to 10 in 13 games, which McClaren hailed as 'phenomenal'.
The Liverpool hitman has even sparked far-fetched suggestions that he could be on course for Sir Bobby Charlton's all-time England record of 49 goals.
Defoe desperately needed his two goals to restore his self-belief after two barren years on the international scene and to help him overcome Sven-Goran Eriksson's flawed decision to dump him from the World Cup squad.
McClaren said: 'The competition in that area is very good and the more of these players scoring then the better it is for me.
'The pleasing thing for me is that Andy Johnson came on and did well, we've got Jermain Defoe and Peter Crouch scoring and we've still got Wayne Rooney and Michael Owen to come back.'
McClaren has already proved he will not pick his team on reputation by omitting David Beckham and he has another big decision looming with Joe Cole close to fitness.
Cole was one of England's better players in the World Cup finals but he has missed the start of McClaren's reign with a knee injury picked up in pre-season.
The England manager has made a big deal of his desire to play with width and pace and Stewart Downing has given his team great balance on the left.
Cole is not naturally left sided but he was shoe-horned into that role by Eriksson and has made a decent fist of it over the last 18 months.
If McClaren wants a player to hug the touchline, offer directness and deliver early crosses, however, then it is not Cole's style.
One player unlikely to pose McClaren a selection problem in the near future is Owen, who dropped in for lunch with the squad at their team hotel in Manchester, on Friday.
The Newcastle striker is about to have an operation on the knee ligaments he damaged against Sweden in the World Cup finals and will miss most of the season.
McClaren said: 'Our thoughts are with Michael. He remains one of England's key players and he is certainly not forgotten. I wish him a speedy recovery.
'He most definitely has a role to play for England in the future and I am looking forward to welcoming him back into the fold.'
McClaren now turns his attention to Macedonia, who drew 2-2 with England in Southampton, four years ago.
The England boss said: 'We have come across Macedonia before and we know that it will be a tough game in Skopje but my belief is that it will be down to us not the opposition.
'People are certainly not getting carried away just yet but I think the optimism is there once again both from the people with in the game and from the public.'