The former Celtic gaffer was appointed by the Scottish Football Association last week as replacement for Craig Levein, who was sacked in November, and Latics centre-back Caldwell believes they have got the right manager.
"I had a great relationship with him at Celtic and spent three great years with him," he said.
"He's a great choice for Scotland and I think he was the only choice, really, when you see the people who were up for it. He was definitely the stand-out choice and I'm glad the SFA have got him.
"He will bring a real passion to Scotland. You could see in his press conference how proud he was to get the job, it means a lot to him."