A second-half double by striker Filip Duricic sunk a much-changed Scotland side and left them bottom of Group A with two points from six games and on the end of their fourth successive qualifying defeat.
However, the Scots boss said: "I said that we might have to take a few slaps but we have to do something, we can't keep plodding along and hoping something happens. I want to pick players that will make things happen."
He added: "Unfortunately for players like Shaun Maloney and Steven Naismith, the conditions weren't great for them but they can't be embarrassed. Sometimes when you have played a game of football, as long as you have given it your best shot you can hold your head up high. Sometimes the other team is better and that is what happened.
"We played against top players, technically gifted, strong, so the physical side the conditions gave us a bit of a problem but in saying that, we stood up to it and the longer the game went on the better we felt about ourselves."
Strachan praised his side for their "big hearts" in the wake of what was a routine defeat for the visitors who now have to build towards the 2016 European Championship qualifiers.
He said: "I think the players were surprised by the conditions which is a problem if you have smaller lads to play in it but we didn't have a physical side on the bench, they were all smaller lads except for Charlie Adam. But they have got big hearts, technically and physically they weren't as good as the lads for Serbia but they had big hearts.
"It was a team put together, they are young, two made their debuts, players at their clubs who are not getting games regularly, players like Steven Whittaker who has not played for three months put his name forward to play, so that shows they have got big hearts.
"So in the next couple of years we have to keep the best youngsters, the best of the players who are missing and a group in the middle and if we can merge that then we can try to produce some football to the standard we have seen in Serbia.
"They are a nation the same size as us, seven and a half million people, we are five million, so we will have to do the same. I don't think we will get as quick to their level in one or two years, we have to build up to that and have a platform where we are winning games and feel better for ourselves."