Craig Levein says he enjoys hearing complaints over players not getting into his Scotland squad because it means his side are getting stronger.
In-form Leeds United forward Ross McCormack was omitted from last month's Euro 2012 double-header, prompting manager Simon Grayson to admit he was "bewildered" by the snub.
Scotland boss Levein concedes the 25-year-old was unlucky to miss out and says he remains in his plans but feels the competition for places can only be a good thing for his side.
He told the Daily Record: "I make absolutely no apologies for people not getting in the squad, I want it to be really difficult to get in.
"I'm happy to hear people complaining they couldn't get in the Scotland squad because that's how it should be.
"People playing well and not getting in the squad is an indication that we are getting stronger. It's a standards thing."
He added: "In the case of Ross McCormack he is very much part of our plans.
"It was unfortunate for Ross. But it should be difficult to get a game for Scotland and you need to come in and make an impact when you join the squad."
Levein says the arrival of Brighton hitman Craig Mackail-Smith on the international scene has made things tougher for both McCormack and Blackburn striker David Goodwillie.
"Mackail-Smith is a recent example - he comes in, gets the chance to make his debut, scores and then plays a really good game against Spain," he said.
"That's encouraging for me but what it does is make it harder for McCormack. It also makes it harder for Goodwillie, who was in the squad."