Scotland assistant manager Mark McGhee accepts Friday’s qualifier away to Lithuania is the first of four must-win encounters in the bid to reach the 2018 World Cup in Russia.
Gordon Strachan’s men are four points adrift of second-placed Slovakia in Group F in the chase for a play-off position, with only four Group F matches remaining.
After a poor start to the group, Scotland have shown improvement in their last two matches with a 1-0 triumph against Slovenia in March followed by a 2-2 draw against group leaders England in June, in which the Scots were seconds away from victory against the Auld Enemy.
McGhee knows that will count for nothing if Scotland lose in Vilnius on Friday, with Lithuania having already secured a 1-1 draw at Hampden Park last October.
McGhee said: “If we are going to qualify – or even have a chance of qualifying – we have to win this game.
“We can’t hide from that. Even if we win this one we cannot be sure of making it but we have to assume that to get through we need to win the four games.
“After the England game and the Slovenia game it wouldn’t just be one step back, it would be a big step back if we don’t go and win this game.
“I go back to the first Lithuania game and we are a better squad now than we were then. Players have improved and one or two have come in and made a difference. Stuart Armstrong, for instance.”
Friday’s match will be played on an artificial surface at the 5,067 capacity LFF Stadium but McGhee will not be looking for excuses.
He added: “The ball runs in a different way and the game should be played on grass but equally we have to respect other people’s needs and the climate they have to allow for.
“We can’t complain. We have artificial pitches in our top division, so there’s not much we can say.
“I know we don’t play international games on them but other countries have done it, so they are not doing anything unique.
“It’s the modern-game and we won’t mention it. We won’t talk about it – we’ll just train on it.”