The teams are level on points at the top of Group B at the half-way stage of qualifying with Belgium perched on the summit thanks to a better goal difference.
Israel are currently third on nine points and crucially, Cyprus are another three points adrift in fourth.
In this campaign, the top two teams from nine qualifying groups go straight through to the finals in France, alongside the third-placed team with the best record. Those 19 teams join hosts France with the remaining eight third-placed teams playing-off for the final four places.
Suffice to say, victory for either team in Cardiff tonight and they will be knocking on the door of the finals - and for Wales, that will mean a first major tournament since 1958.
"It's a huge game in the group because I think whoever wins will probably take first place and keep it until the end of qualification," said Nacer, who is with Spurs team-mates Mousa Dembele and Jan Vertonghen in the Belgian squad.
"We are playing for first place and we have to try to win this game."
Another Spurs team-mate, Ben Davies, misses this match for Wales due to injury, but with the likes of Ashley Williams, Joe Allen, Aaron Ramsey and of course Gareth Bale coming to the fore, Wales are a force to be reckoned with - as Nacer knows too well.
"Wales are a very good team," he added. "I think they escaped from Belgium with a draw because we had a lot of chances in that game but now we play away and it will be difficult.
"They will be more confident at home but we still have a good team and I'm sure it will be a good game to watch."