- Watch: Reus' injury (US, UK only)
- #WorldCupRank No. 33: Marco Reus
The Dortmund winger rolled his ankle during Germany's 6-1 win over Armenia in a friendly on Friday night, and Die Mannschaft confirmed the extent of Reus' injury on their official website.
Reus' was seen crying on the side of the pitch after being taken off.
He was taken to Mainz University Hospital, according to Bild, which reported Reus tore his anterior tibiofibular ligament between the tibia and fibula.
The injury will not require surgery, Bild reported.
After the game, coach Joachim Loew said: "We can only hope that he will be OK. But it looked bad. We can call up another player until 24 hours before the first game."
Lukas Podolski replaced Reus in the game against Armenia, scoring once and setting up two more goals.
Germany face the United States, Portugal and Ghana in Group G, with their first game against Portugal on June 16.