The 34-year-old Real Madrid goalkeeper will only be available for next fall's European Championship qualifiers.
Courtois made his 115th and final international appearance at this summer's World Cup. Belgium's new national team coach, Mark Van Bommel, has already informed Courtois that he is not seen as an automatic first-choice goalkeeper for the national team.
However, Courtois has left the door open to playing in the Nations League if the national team suffers a crisis of injuries among its goalkeepers.
With Courtois absent, Senne Lammens, the 24-year-old at Manchester United, and Chelsea's 21-year-old Mike Penders are two of the options.
Belgium plays in the same group as France, Belgium and Turkey in the Nations League.
