The Manchester United youngster ended speculation over his international future by pledging his allegiance to Belgium last month, and was duly named in Marc Wilmots' provisional 24-man squad for the World Cup.
Januzaj's decision to declare for Belgium has been met with a mixed reaction from their existing squad.
Captain Vincent Kompany has welcomed his inclusion, but winger Kevin Mirallas went on record last month as saying the 19-year-old should not go to Brazil on the basis that he did not feature often enough for United in the second half of the domestic season.
Playmaker Januzaj started only 15 of United's 38 Premier League fixtures in 2013-14, but did enough to convince Wilmots he could add something to a squad that reached the World Cup at a canter.
Belgium won eight and drew two of their 10 qualifying fixtures, and are seen by many as dark horses for Brazil 2014 after being drawn in Group H alongside Russia, South Korea and Algeria.
Wilmots' side have lost just one of their last 18 competitive fixtures, and the coach could take an experimental approach to Monday's game as a number of his stars - such as Kompany, Eden Hazard and Romelu Lukaku - are likely to be fatigued after demanding domestic campaigns.
One man Wilmots will definitely be without in Genk is first-choice goalkeeper Thibaut Courtois, who will play for Atletico Madrid in Saturday's UEFA Champions League final meeting with Real Madrid.
However, a second-string Belgium XI would still likely be far too strong for their neighbouring minnows Luxembourg - who are positioned exactly 100 places below them in the world rankings.
Luxembourg can take a glimmer of hope from Belgium having not won any of their last four friendlies.
However, Luc Holtz's team have won just two of their last 18 matches, with their most recent away victory coming in a World Cup qualifier in Switzerland back in September 2008.
Holtz oversaw just one win in Luxembourg's World Cup qualification campaign - a 3-2 success over Northern Ireland last September - and would appear to face an uphill struggle to keep the score down at the Cristal Arena.
