Gedion Zelalem’s Under-20 World Cup is reportedly over, and it appears the injury sustained in the U.S. Under-20 Men’s National Team’s opener is much, much worse than originally feared.

According to Football.London, Zelalem ruptured his anterior cruciate ligament in the Americans’ 3-3 draw with Ecuador on Monday. Zelalem was removed from the match in the first half due to a non-contact injury and was replaced by Derrick Jones.

The midfielder will reportedly miss six-to-nine months.

Zelalem, who is under contract with Arsenal until the end of the 2018 season, spent the second half of last season with VVV Venlo before joining up with the U-20s for the World Cup.

With Zelalem’s injury, the U.S. has just four central midfielders on the roster in Jones, Tyler Adams, Luca de la Torre and Eryk Williamson.

The U.S. U-20s return to action Thursday to take on Senegal in the second match of their group stage run.