The 22-year-old missed the 4-2 win at Motherwell on Saturday due to a quad issue which has now forced him to withdraw from the upcoming age-group internationals against Czech Republic and Japan.
Raskin confirmed the news on his Instagram page on Monday, posting: "Unfortunately I will not be playing for Belgium U-21 in the upcoming two matches due to a small injury. I'll be back soon!"
The January signing from Standard Liege, who has been in impressive form since joining Rangers, now faces a race against time to recover his fitness ahead of the resumption of domestic football after the international break.
Rangers return to action with a Premiership fixture against Dundee United at Ibrox on Saturday, April 1 before the trip to Celtic Park for the latest instalment of the Old Firm derby the following weekend.