The two sides will square off in the final game of Group A in the European section of qualifying, with Marc Wilmots' charges already securing top spot by dropping just two points in nine matches.
By contrast, Wales have endured a frustrating campaign losing six games, and have little to play for other than to improve their coefficient ahead of future qualifying phases for the World Cup and UEFA European Championships.
Coleman admits his depleted squad face a difficult challenge in getting a result against a Belgium team who have won seven of their last eight fixtures, and believes they will have a huge impact on the marquee tournament.
"They were 40th in the world when we first played them in Cardiff at the start of the campaign," said Coleman. "Now, they are sixth.
"They are a very good team. We've been doing our homework on them and pound for pound and player for player, they have the most expensive squad in the world.
"I'd fancy them at the World Cup. They have a real outside chance. They are a very good team.
"It's a difficult test for us on Tuesday night.
"I don't think there will be many teams looking at them thinking, 'We'd like to play them'."
Belgium's squad for the clash in Brussels has cost club sides plenty with the likes of Eden Hazard, Marouane Fellaini, Axel Witsel and Romelu Lukaku having all moved for eight-figure sums in their careers.
But Coleman believes his star midfielder Aaron Ramsey would be worthy of a place in any side in world football, following another stellar performance in Wales' 1-0 triumph over Macedonia on Friday.
Arsenal man Ramsey has scored nine goals in 14 games for club and country this season in a magnificent start to his 2013-14 campaign.
He added: "I'd put Aaron in any team because of the way he is playing. There's not a manager who wouldn't have him in his team every game.
"He could play in the Belgian team, absolutely, and I don't say that because I'm Welsh. He's that good."
