Pep Guardiola has refused to confirm the extent of a knee injury which has ruled Bastian Schweinsteiger out of the DFB Pokal final.
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The Bayern Munich midfielder will miss the game against Borussia Dortmund after limping out of the final game of the Bundesliga season last Saturday, a 1-0 win against Stuttgart.
At a news conference ahead of Saturday's final, Guardiola said: "He is injured. Bastian has problems with his knee." When questioned on whether he will be fit for the World Cup, Guardiola added: "I am not a doctor."
The 29-year-old has been included in Germany's World Cup squad but it remains to be seen whether he will recover sufficiently in time to travel.
Schweinsteiger was expected to have an MRI scan earlier in the week in order to determine the full extent of the injury.
Germany are due to hold a pre-tournament training camp in Berlin following the cup final. It is the latest injury blow for Schweinsteiger, who underwent two operations on his right ankle in the past year.
He has over 100 caps for Germany and appeared in the 2006 and 2010 World Cups.