David Marshall, the Cardiff City goalkeeper, played 90 minutes of the 1-0 Warsaw friendly victory over Poland and carried his club form into the international arena with some important saves. But Strachan insists that decision was for one game only and he expects to have to make a tough choice when the Euro 2016 qualifiers begin in September.
"I spent about one hour and 40 minutes making decisions on Tuesday night," he said. "And that says a lot. If you have to spend one hour and 40 minutes talking about who to pick and who not to pick, you know the squad is getting stronger.
"[Steven] Naismith and [Steven] Fletcher, Marshall and McGregor - a toss of a coin. When it comes to the nitty gritty it gets tougher."