The Motherwell boss, who represented his country 40 times during his playing career, joins Strachan and Mark McGhee in the new national set-up.
He said: "I'm absolutely honoured to be asked along to be part of the national set-up and also with it being Gordon asking me, I'm just really honoured and proud.
"Anyone who knows me, other than my accent, I'm 100% committed to Scotland.
"I played against Gordon and came across him but I don't really know him that well, the same with Mark, but we had a good relaxed chat when we met up on Monday night.
"I never thought in my wildest dreams I would be anywhere near the national set-up and it came out of the blue.
"I'm thrilled to be given the opportunity to work with good players and to be involved in the set-up.
"And not only that, to work under both Gordon and Mark, who are both experienced managers and coaches, it will benefit myself, and seeing good players up close, even the opposition as well.
"We'll see how it goes but obviously I've spoken to Kenny Black, my assistant at Motherwell. One or two of the staff are giving me stick for coming in and taking his job.
"I used to actually be quite envious of Kenny when he went away with Scotland – because he was going away with Scotland and it left me with the rest of the lads at Motherwell, which was hard work.
"But he is pleased for me as well and I think it will be a similar role."