The Cardiff goalkeeper appeared to suggest that finding a settled team for the future was the key concern for Scotland after their fourth consecutive qualifying defeat left them bottom of Group A with two points. Scotland next face Croatia in Zagreb before home games against the Croatians and Belgium and a game against Macedonia in Skopje.
Asked whether Scotland could contemplate going through the whole campaign without a victory, Marshall told BBC Scotland: "I don't think it matters, you either want to qualify or you don't qualify. It doesn't matter if you are getting beaten every game or if you finish third, you are still not qualifying."
He continued: "I think the main thing for us, it's a new manager so things are going to take time to gel. But it's earlier on in the campaign that we have been disappointed with. I think in the next few games when the gaffer gets a settled side, it will definitely pick up."
When asked whether former Wales international Mickey Thomas - who last week claimed this Scotland team was the worst in the nation's history, had a point, Marshall said: "We don't really care to be honest. I live in Cardiff and Wales lost six (against Serbia) just a few months ago and they were saying the same about Wales down there.
"It's swings and roundabouts. We just have to turn draws and defeats into wins, end of story, and shut people up. If Mickey Thomas wants to say it's the worst team in history, I think it's just a cheap slur. We will just get on with it and the only thing we can do to shut people up like that is to win games."
There was little former Celtic goalkeeper Marshall could do about the two goals by Filip Duricic, which came in quick succession after Jordan Rhodes had shot straight at the goalkeeper in Scotland's best chance of the night, just before the hour mark.
Marshall said: "It was a disappointing night eventually. I thought first half we did okay, we defended pretty well the first half hour and limited them. Even at the start of the second half we had a few chances. Jordan has had a chance just before they scored. It's a difficult pitch, and it was a difficult chance.
"They have had a bit of luck with the deflections that led to their goals. It's just disappointing that after a good first-half performance we have let in two goals in quick succession. We have not won a game in the group, we have disappointed ourselves and let down the fans as well. It is a low dressing room.
"We still believe we can get victories but we just need to work hard to turn it around. There is nothing else we can do apart from get on with it."