The 65-year-old has coached his nation twice but will be in the opposite dug-out on Saturday as he bids to put a spanner in their World Cup preparations
Belgium face against former coach Georges Leekens on Saturday as Tunisia provide the opposition in their final World Cup warm-up match.
Leekens has managed his home nation twice, with the most recent spell ending in 2012, and he will hope his knowledge of the current squad can help the African nation cause an upset.
After qualifying for their first World Cup in 12 years, Belgium travel to Brazil as one of the favourites after impressing throughout qualifying and possessing a squad brimming with talent.
Even though striker Christian Benteke will miss the tournament through injury, coach Marc Wilmots still has a plethora of attacking options to choose from, with Romelu Lukaku making his claim for a starting role with four goals in their two recent warm-up matches.
Axel Witsel impressed in the centre of midfield during the 5-1 win over Luxembourg and 2-0 victory against Sweden, leaving the 25-year-old feeling positive heading into the final preparation game.
"The team is ready," Witsel told Het Nieuwsblad. "In the main, everyone is serene.
"There is no nervousness. We know what we can set ourselves without putting any extra pressure on."
Tunisia should not be taken lightly. They have lost only lost twice in their last 12 outings and beat South Korea 1-0 in Seoul last week to show that they are no pushovers.
That win came in Leekens' first match in charge since being appointed in March and he is relishing his return to Brussels this weekend.
"I come to Brussels as a proud Belgian," he said.
"The dream (of reaching the World Cup) has become a reality for the whole country.
"I am glad that I have contributed to that, (and) am looking forward to seeing many friends."
With only a week to go before the tournament in Brazil starts, Belgium will be keen to avoid any injury scares, although Wilmots is likely to play a strong side to keep the side's momentum going.