Clarke confirmed that he will reveal an interim World Cup squad at the “start of May”, the former Chelsea and St Mirren full-back joking that he would include himself if using all of the 55 places available.
Scotland host Curacao on 30 May before travelling to the USA, where they will take on Haiti, Morocco and Brazil in Group C.
“I’ve been looking for seven years, it’s not about the last six weeks,” Clarke said of the selection process.
“Where is the next talent? How are we going to improve the squad? That’s my job.
“I understand what we’ve got. I’ve got a really good idea of what’s coming next and there’s one or two even younger that I know about. And there’s maybe one or two with other countries at the moment that you are thinking ‘maybe in the future we can persuade them to help the national team’.”
Clarke has steered Scotland to three of the past four major finals, ending a 28-year absence from the World Cup.
“I can only pick 26,” he said of his tournament squad. “For the younger ones in and around that, their ambition has to be the next tournament – and then the next tournament.
“If you can build that determination then we don’t go 20 years without qualifying because the next group of players are as hungry as this group. We’ve got that mentality now, but it needs to run.
“Now we expect to qualify. The players know how to get points from a qualifying group. We finished above two good teams [Denmark and Greece]. We didn’t always play at our best, but we found a way to get points at the right time.”
