The Motherwell boss has been amazed that players have reported for duty in Aberdeen – even though they have no chance of being involved against Estonia.
And McCall, who was appointed to Strachan's backroom team, believes that bodes well for the friendly at Pittodrie tomorrow night.
He said: "Everyone wants to be here. There are one or two players with knocks who may not be involved and will have to be monitored who are here.
"But all the players are turning up. That is what you want when you are trying to get togetherness.
"Alan Hutton is now playing in another country. It will take him a little time to settle in Spain, But he took three flights to get to Aberdeen.
"Under Craig Levein and his team there were no bad apples. I think there was a sense that there was a strong team ethic.
"Even when Craig departed a lot of players came out and said that team harmony was not a problem."
Former Everton, Rangers and Scotland midfielder McCall is optimistic the national side can score goals in Strachan's first game in charge tomorrow.
A host of Scotland internationalists netted for their clubs in England at the weekend – Gary Caldwell, Shaun Maloney and Jordan Rhodes.
And the 40-times capped player believes ex-Celtic gaffer Strachan will reward men who show creativity in the final third and an ability to hit the target.
McCall stated: "There are a lot of players who are doing well down south at the minute in the middle to front areas.
"Jordan Rhodes scored two at the weekend, Shaun Maloney scored and Gary Caldwell scored. On top of that, Steven Fletcher has been scoring.
"Then there are Robert Snodgrass and James McCarthur. There is a lot ability there, players who can beat people.
"That is what the gaffer is looking for – a bit of individual magic, like he used to do.
"But Estonia have had some decent results of late and we will have to be at our best on the night to get the result.
"In days gone by everyone would have been saying that Scotland should be beating Estonia. It won't be straightforward, but hopefully we can do that.
"This is a friendly, but we still want to build momentum for the qualifying double header coming up."