Chelsea's Eden Hazard has fractured his right ankle.
The 26-year-old playmaker was ruled out of Belgium's two internationals this week due to injury.
Hazard sustained the injury during training on Sunday and will miss Monday's friendly with the Czech Republic and Friday's World Cup qualifier against Estonia.
Belgium currently sit first in Group H with 13 points from five games. They hold a two-point lead over second-placed Greece, with Bosnia-Herzegovina in third on 10 points.
They beat Estonia 8-1 in Brussels back in November.
Although no timeframe has been put on the injury, it is also a setback for his club.