Shiels' team attained the Euros in historic style in April but he believes the World Cup qualifying arrangement works contrary to"smaller countries".
"The World Cup is so much harder compared to Euros," he explained.
"I know the World Cup is our second juncture but I think it would be foolhardy for us to chat about qualifying for the finals.
"With the draw, it is being supplied more and more for the very best nations to qualify because they want all the best teams on the planet to be in the World Cup.
"I think the Nations League from the men's game could be a good copyright for people to look at. The women's game could be moving that way at which it allows the smaller countries to play against the smaller countries and eventually become a more functional game, where it's a good challenge for both teams."
While Northern Ireland are enjoying a game for the first time since they beat Ukraine in their Euro play-off in April, Scotland enter Thursday's game at Seaview looking to bounce back from falling despite having been top seeds in their qualifying group.
High-profile Northern Ireland gamers such as Rachel Furness, Ashley Hutton and Demi Vance are out injured, while Everton forwards Simone Magill is unavailable as she's place to get married at the weekend.
"We do not need to conquer Scotland but we have to be careful we do not miss the winning mentality," he continued.
"Obviously we want to win against Scotland but it is not at the very top of the priority list. At the very top of our priority list is to get players to enhance and to play better in the big games.
"Luxembourg is a far bigger game compared to Scotland, as is Latvia [NI's next qualifier], and that is exactly what this game is preparing us .
"But we have got total respect for Scotland who have a huge pool of players playing in the big leagues in Europe and England. Twenty-one of their squad are full-time professional gamers, so that is the Size of the sport and we will do our best."
With the Euro finals in England next summer coming in the middle of World Cup qualifying, Shiels is thinking carefully about the way he intends the squad's development.
"There is a pathway there for us now that we must get ready for and it's a challenging one because we go out of this Euros pathway, into the World Cup pathway then back into the Euros pathway.
"This is a tiny bit'juggly'. The Scotland game is to assist the gamers top up on their sport fitness. Hopefully we'll learn some thing from Scotland also it will help the women to get to a positive pathway."