The 18-year-old Anderlecht central defender is the only newcomer but Martinez said his inclusion should not be considered a surprise.
“It is no surprise because of the impressive way he has started the season,” he told a news conference on Friday.
“The progression of a player is linked to what they do at club level and he has been a very impressive player with a huge role. Then you stop looking at the age and rather look at his potential,” the coach added.
Martinez also picked Jason Denayer but he will not play either game because he has not found a new club since leaving Olympique Lyonnais at the end of last season. Instead he will only train, Martinez explained at a news conference on Friday.
“It’s not an optimal situation but a lot of things can still happen,” he said.
Top scorer Romelu Lukaku misses out because of injury but Martinez said he had no concerns over the Inter Milan striker’s availability for the World Cup in November.
“His treatment is going in the right direction and he will be fit for his club very soon.”
Belgium take on Wales in Brussels on Sept. 22 and the Dutch in Amsterdam three days later. Belgium are second in League A Group 4, three points behind leaders Netherlands.
Squad:
Goalkeepers: Koen Casteels (VfL Wolfsburg), Thibaut Courtois (Real Madrid), Simon Mignolet (Club Brugge), Matz Sels (Racng Strasbourg)
Defenders: Toby Alderweireld (Royal Antwerp), Dedryck Boyata (Club Brugge), Timothy Castagne (Leicester City), Zeno Debast (Anderlecht), Jason Denayer (unattached), Wout Faes (Leicester City), Brandon Mechele (Club Brugge), Thomas Meunier (Borussia Dortmund), Arthur Theate (Stade Rennes), Jan Vertonghen (Anderlecht)
Midfielders: Yannick Carrasco (Atletico Madrid), Kevin De Bruyne (Manchester City), Leander Dendoncker (Aston Villa), Thorgan Hazard (Borussia Dortmund), Dodi Lukebakio (Hertha Berlin), Alexis Saelamaekers (AC Milan), Amadou Onana (Everton), Youri Tielemans (Leicester City), Hans Vanaken (Club Brugge), Axel Witsel (Atletico Madrid)
Forwards: Michy Batshuayi (Fenerbahce), Charles De Ketelaere (AC Milan), Eden Hazard (Real Madrid), Dries Mertens (Galatasaray), Lois Openda (Racing Lens), Leandro Trossard (Brighton & Hove Albion).
