Loew hoping to solve goalkeeper dilemma
Loew said Bayer Leverkusen's Rene Adler would keep goal in the friendly at home to 2010 World Cup hosts South Africa on September 5, while Hanover 96's Robert Enke would step in for the World Cup qualifier against Azerbaijan four days later.
Adler has made four appearances and Enke eight.
Germany lead European Group Four with 19 points from seven games, four ahead of second-placed Russia who have a game in hand.
The Germans must still visit Russia in October where defeat could condemn them to a second-place finish in the group and a possible two-leg playoff for a place in South Africa.
"We hope to have settled the goalkeeper question in time for the matches against Russia in Moscow and Finland in Hamburg in October," Loew said on the German Football Association's website.
Goalkeeper trainer Andreas Kopke added: "By the end of the year, we want to have given all four of our World Cup candidates the chance to have played at least 90 minutes. That's a fair rule for everyone."
VfB Stuttgart midfielder Sami Khedira was the only uncapped player in the squad.
Goalkeepers: Rene Adler (Bayer Leverkusen), Robert Enke (Hannover 96), Manuel Neuer (Schalke 04)
Defenders: Andreas Beck (Hoffenheim), Arne Friedrich (Hertha Berlin), Philipp Lahm (Bayern Munich), Per Mertesacker (Werder Bremen), Marcel Schaefer (VfL Wolfsburg), Serdar Tasci (VfB Stuttgart), Heiko Westermann (Schalke 04)
Midfielders: Michael Ballack (Chelsea), Christian Gentner (VfL Wolfsburg), Thomas Hitzlsperger (VfB Stuttgart), Sami Khedira (VfB Stuttgart), Marko Marin (Werder Bremen), Mesut Ozil (Werder Bremen), Simon Rolfes (Bayer Leverkusen), Bastian Schweinsteiger (Bayern Munich), Piotr Trochowski (Hamburg SV)
Forwards: Cacau (VfB Stuttgart), Mario Gomez (Bayern Munich), Miroslav Klose (Bayern Munich), Lukas Podolski (Cologne)