Belgium's Vincent Kompany, Toby Alderweireld, Jan Vertonghen, Dries Mertens and Moussa Dembele were all pictured sharing a laugh on the training pitch as they all caught up.
Further recruits are expected in Eden Hazard and Thibaut Courtois who are due to fly out today (Tuesday).
Marouane Fellaini and Adnan Januzaj of Manchester United were also in attendance, as Marc Wilmots prepares his side for their first qualifiers.
They share a group with Wales, Bosnia, Cyprus and Israel, as well as Andorra who they face at home on Friday.
Belgium then face a tricky looking trip to fellow World Cup nation Bosnia on Friday, where Vincent Kompany will go head to head with Manchester City teammate Eden Dzeko.