James Morrison is clinging on to the belief that Scotland's World Cup qualification hopes are still alive despite crashing to Wales in Cardiff on Friday night.
However, the West Brom midfielder admits anything less than a win against Group A favourites Belgium on Tuesday night will deliver the fatal blow to their chances of reaching Rio.
Morrison said: "There is probably a little bit of hope if we win in Belgium. We get that belief again and that's all we can do. We've got to regroup quickly or else the group is going to pass us by."
He added: "Basically, we've got to win in Belgium. We've just got to remain positive, that's all we can do. They are probably the favourites for the group and they've got some great players but we can't think too much about it.
"We just need to get on with it and look forward to the game. They are a good team but football is a funny game. We will go there and try to regroup and get a game plan and take it into the Belgium game."
The Scots threw away a one-goal lead - courtesy of Morrison's first-half opener - when a late double from star man Gareth Bale handed Wales their first win of the Chris Coleman era. Craig Levein's men have just two points from their opening three games leaving them second bottom of the table.
Section leaders Belgium showed again why they are regarded as group favourites with an impressive 3-0 win in Serbia on Friday night, with Scotland now facing a massive challenge as they aim to pull off a shock result in Brussels.
There was a sense of injustice in the Scotland camp following the defeat at the Cardiff City Stadium. The penalty which sparked a Welsh comeback - won and converted by Bale after going down in the box under pressure from Shaun Maloney - appeared to be a soft decision and was the subject of debate afterwards.
Worse for the Scots was the assistant referee's call to disallow what appeared to be a perfectly good Steven Fletcher goal after ruling Charlie Adam's cross had swung out of play, when television footage appeared to suggest otherwise.
Morrison said: "We've been done by the linesman. I don't know what he has seen. At 2-0, I think we would have won the game. It's a clear goal so that's probably the main disappointment."