Former German international Thomas Berthold has criticised Per Mertesacker.
Despite being favoured by many to put out hosts Brazil, there is a feeling the side has weaknesses and is not clicking at 100 per cent just yet.
Former German international Thomas Berthold believes veteran defender Per Mertesacker is a player who opponents can exploit.
He told Sport1.de: "In the center of defense back Mats Hummels and Jerome Boateng should start. For my taste, Per Mertesacker is just too slow, I have pointed this out before the World Cup."
Mertesacker took much criticism in Germany after the second round win over Algeria, in which the team's high line was regularly exposed, only saved by 'sweeper-keeper' Manuel Neuer.
The defender did not feature against France, left out after failing to recover from illness, and his place in the team against Brazil is far from assured with Boateng stepping into help Germany keep a clean sheet.
Berthold, a former central defender himself with 62 caps for Germany, also believes many of the squad are unfit, evidenced by their performances in the second half of games dipping.
He has pointed out Sami Khedira, Bastian Schweinsteiger and Mesut Ozil as three of these, describing them as 'not in the best physical condition.'
"I would like to see the way that Andre Schurrle is in the starting line-up. For me he is the most dynamic player of the team in this tournament and fast players are enormously important."
Against a Brazil defence which boasted the suspect Maicon against Colombia, and will be without Thiago Silva, a direct threat like Schurrle could be crucial.
With manager Jogi Low flip-flopping between playing Phillip Lahm in midfield and defence, and starting Miroslav Klose up front or not, Germany's team selection is far from assured on many levels.
Big decisions await regarding two excellent Premier League performers in Schurrle and Mertesacker, and getting them right or wrong could just be the difference between getting past Brazil or elimination.