Former Republic of Ireland captain Matt Holland feels failing to reach an extended Euro 2016 finals would be viewed as a missed opportunity for Martin O'Neill's squad.
Scotland head to Dublin for Saturday's Group D encounter looking to put another dent in the Republic's hopes of reaching France next summer, following their 1-0 victory in Glasgow in November.
Leaders Poland are a point ahead of Germany and the Scots, but Ireland are only three behind.
Holland, who earned 49 international caps and played at the 2002 World Cup, expects a response in Dublin, but knows there is now little further margin for error.
"The last Euros did not go to plan, and it would be nice to qualify for this one, particularly with it being extended to 24 teams. It would probably feel a bit of a missed opportunity if we don't make it this time," Holland told Press Association Sport.
"It is a tight-knit squad, we have some very good players and if we can find some goals from someone other than Robbie Keane, I think we have a chance."
Holland, who is taking part in the Prostate Cancer UK London to Amsterdam bike ride, added: "It is a must win game now on the back of losing in Scotland.
"But we are in the most competitive and tighest group.
"You would imagine Germany would rise to the top, then Poland, Scotland and ourselves are all right in the mix."
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