Wigan's Caldwell confident Scotland squad continually improving
Ahead of a friendly with Australia in Edinburgh on Wednesday, the centre-back spoke of the quality of players in Craig Levein's roster these days and how they have more ability than squads he has been involved with in the past.
"Over the last few years we have shown there is a bigger group than the 22 players who can be picked in a squad," he said.
"You just need to look at the squad list and see the amount of players playing in the Premiership in England and the Championship, which is a fantastic league.
"I think the overall quality in the players that are getting picked is better than the groups I have been involved in in the past.
"But it's no good saying that, we have to go out and show that in every game we play."