Marco Reus has been ruled out of the World Cup after suffering an ankle injury in Germany's 6-1 friendly win over Armenia.
The Borussia Dortmund midfielder, 25, sustained a partial tear of an ankle ligament and is expected to be out for six or seven weeks.
"For him and for us this is extremely regrettable," said Germany coach Joachim Low.
Sampdoria's former Everton defender Shkodran Mustafi has replaced Reus.
Reus's withdrawal is a major blow to Germany's World Cup preparations, with Bayer Leverkusen midfielder Lars Bender already ruled out with a thigh injury.
But despite losing another midfielder, Low has decided to call up defender Mustafi, who was at Goodison between 2009 and 2011 but made only one substitute appearance before moving to Italy.
"It is not about us replacing Marco Reus one on one," said Low.
"Our quality in the position behind the strikers is very high. We have Lukas Podolski, Andre Schurrle, Mario Gotze, Thomas Muller, Mesut Ozil, Julian Draxler and Toni Kroos to give us plenty of alternatives.
"That's why we decided for another option for the defensive area. Shkodran impressed us in training camp, he's fit, we have confidence in him."
Goalkeepers: Manuel Neuer (Bayern Munich), Roman Weidenfeller (Borussia Dortmund), Ron-Robert Zieler (Hannover)
Defenders: Jerome Boateng (Bayern Munich), Erik Durm (Borussia Dortmund), Kevin Grosskreutz (Borussia Dortmund), Benedikt Howedes (Schalke), Mats Hummels (Borussia Dortmund), Philipp Lahm (Bayern Munich), Per Mertesacker (Arsenal), Shkodran Mustafi (Sampdoria).
Midfielders: Julian Draxler (Schalke), Matthias Ginter (Freiburg), Mario Gotze (Bayern Munich), Christoph Kramer (Borussia Monchengladbach), Sami Khedira (Real Madrid), Toni Kroos (Bayern Munich), Thomas Muller (Bayern Munich), Mesut Ozil (Arsenal), Andre Schurrle (Chelsea), Bastian Schweinsteiger (Bayern Munich).
Forwards: Miroslav Klose (Lazio), Lukas Podolski (Arsenal).