Germany will not risk playing centre back Mats Hummels in their Euro 2016 Group C game against Poland on Thursday unless he is "100 percent fit", coach Joachim Loew said.
Hummels missed the world champions' opening 2-0 victory over Ukraine on Sunday and has not played since picking up a thigh muscle injury in the German Cup final in May.
The 27-year-old had not trained with the team until this week, while Shkodran Mustafi replaced him at the heart of the Germany defence in their group opener.
"I will not take any risk if there are any problems or he does not feel 100 percent fit," Loew told reporters on Wednesday. "We will look at the final training (session) this evening.
"But we will talk with the doctors after practice and see.
"Germany's defence will need him, having looked shaky at times against the speedy Ukrainians. Fellow central defender Antonio Ruediger was forced to drop out with a cruciate ligament injury days before the tournament started.
Poland are arguably a more dangerous opponent than the Ukrainians, with a familiar face in Germany, the Bundesliga's top scorer Robert Lewandowski, leading their attack.
"Their biggest strength is that they have a very well-organised team. They wait and lurk and they have a team that can counter attack quickly," Loew said.
"Quick players, who will also go deep with high tempo and they are probably the best counter-attackers I have seen in the past two years.
"Loew would not reveal his plans for his own frontline, after attacking midfielder Mario Goetze was deployed as a forward on Sunday, but was largely ineffective.
Asked whether striker Mario Gomez would play against the Poles, Loew said both were an option.
"Both are in good form. I did not see Mario play as badly as the critics. He worked hard. Gomez is in good form in training and both could fit against Poland.
"Loew, however, ruled out playing captain Bastian Schweinsteiger for the full 90 minutes, after the midfielder came on as a substitute to score their second goal against Ukraine following a long-term injury absence.
"You can feel that he is making physical progress every day...but he still does not have the power for 90 minutes.