The Sunderland striker was unavailable for the Scots' World Cup qualifying double header against Belgium on Friday and Macedonia on Tuesday because of an ankle injury but Strachan admits his side missed the influence of the attacker in Glasgow.
"Sunderland think it is better for Steven to stay, to give him another two weeks when he can play 60 minutes of reserve games and build him up," said Strachan.
"It would be nice to have him here. Just like it would be nice to have Kenny Miller here but he decided to retire. So there are two players you'd probably call on.
"What I can't do is create a monster, build us a striker, make us quicker or taller. I can't stretch Shaun Maloney to be 6ft 2in.
"We have a system away from home that's not too bad. It's finding something at home that will bring us victories."