Reus turned his ankle shortly before the break in their 6-1 victory in Mainz and was taken to hospital.
The German FA confirmed his withdrawal from the tournament on Saturday morning, saying he would be replaced by Sampdoria's Shkodran Mustafi.
A team statement said Reus would return to training in six to seven weeks.
Coach Joachim Loew said: "This is extremely regrettable for us and for him. Marco was in great shape, he made an excellent impression in training campand played well in the friendlies against Cameroon and Armenia. He had a central role in our plans."
Speaking about picking Mustafi, a defender, to replace Reus, Loew said: "It was not about finding a like-for-like replacement for Marco Reus. Our quality in the position behind the strikers is very high, we have plenty of alternatives in Lukas Podolski, Andre Schurrle, Mario Goetze, Thomas Muller, Mesut Ozil, Julian Draxler and Toni Kroos plenty. That's why we decided on another option for the defensive area. Shkodran impressed us in training camp, he's fit, we have confidence in him. We know that we can rely on him 100 percent. "
The lightning-quick Reus, who enjoyed a superb season at Dortmund, was seen as a key player in Germany's quest to claim their first international title in 18 years.
- Sports & Recreation
- Joachim Loew