The Borussia Monchengladbach midfielder trained with the national team this morning, but returned to his club after experiencing back pain after the session.
As a result, the 23-year-old will miss the World Champions' Euro 2016 qualifier with Gibraltar in Nuremburg later on Friday, as well as Tuesday's friendly at reigning European champions Spain.
"Christoph Kramer will not be available for Germany's two upcoming national games due to back problems," read a statement on Gladbach's official website.
"Kramer left Germany's training camp in Nuremberg on Friday after the morning training session.
"Kramer suffered from back pains after the training session. After consulting Borussia, the DFB medical team decided that the 23-year-old should return to Borussia Park to fully recover.
"Kramer will also miss Germany's friendly against Spain in Vigo on Tuesday."
