The Dragons will qualify automatically for next year's tournament in Russia if they beat the Republic of Ireland in Cardiff and Group D leaders Serbia slip up.
Coleman told reporters ahead of Monday's crunch clash: "It is as big as anything we have been involved in. We've got to wear the jersey and give everything you have got.
"I can forgive our players for anything but I can't forgive them if they don't empty on the pitch when they put the jersey on. They always do.
"They were labelled this golden bunch of players before we qualified for a tournament and I fought against that. But they have earned it, this group of players have made a difference. This is their time, they are doing a great job, doing fantastically well.
"It is a golden era, they have proved that but whatever they have done is in the past. We can't be thinking we have done really well, it is not going to help us Monday night."
Euro 2016 semi-finalists Wales have not reached a World Cup since 1958.