The trio have all fallen out of the international reckoning in recent years as a series of injuries and lack of first-team football halted their progress.
Boyd and McFadden have re-signed for first clubs Kilmarnock and Motherwell respectively while Thomson is training with Hibernian as he bids to make his return to action.
On their day, all three would be welcome additions to the international pool, but boss Strachan, who yesterday named his squad for the upcoming World Cup qualifier double header with Wales and Serbia, knows the Scots stars will have to make steady progress on the road to recovery.
He said: "It is great to see him back. I spoke to him recently and he just needs to play games.
"Listen, you need to let them get on with their rehabilitation one way or another.
"Faddy needs to get on with it, he has not played regularly for a few years.
"Kevin Thomson is the same, what a terrific midfield player he is. If Kevin was fit, he would be in the squad. He has to recover and get playing again.
"I think it is best that they get on with it without having the madness that surrounds a Scotland game. They have plenty time."
Strachan has made five changes to his group from his initial pool that beat Estonia 1-0 at Pittodrie in February, with Rangers defender Lee Wallace one of the high-profile absentees.
Celtic captain Scott Brown also misses out due to injury while there is no place for Phil Bardsley, Matt Philips or Jamie Mackie.
Danny Fox and Graham Dorrans are both back in contention and there are first call-ups for Brighton's Liam Bridcutt, Gary Mackay-Steven of Dundee United and Hull striker George Boyd.
Strachan has selected a strong forward-thinking group for the Hampden clash with Wales and trip to Serbia.
And the national boss is keen to make the most of our talented frontline arsenal.
He said: "I don't think I would change it depending on where we are or what situation we are in.
"I picked them because they are good players. Whenever I have been successful, having good players around you is the secret to success. It is finding a formation for these guys.
"I know which way I am going to try and play with and without the ball, now we just need to spend time on it. It is up to the players after that to take their chance."