Bayern head to Signal Iduna Park for German football's traditional curtain-raiser on Wednesday looking to avenge their 4-2 defeat in the corresponding game last season.
The former Barcelona boss will be hoping for a different outcome this time around, but believes he may be hampered by a lack of viable first-team options with many of his squad experiencing a gruelling - yet ultimately successful - World Cup campaign with the German national team.
"We have eight or nine fully fit players, no more," Guardiola said in a press conference on Tuesday.
"I will talk to the players after training and then I'll decide who can play for how long.
"This is a final, and it is not about testing and trying out things. No, no, I am clear about what we need to do.
"I know who our opponents are, how hard it is going to be.
"Dortmund are a great counter-attacking side with a very good defensive structure."
Guardiola also declared that Bayern will not be making any further signings following the close-season arrivals of ex-Dortmund star Robert Lewandowski, Sebastian Rode and Pepe Reina as the likes of Thiago Alcantara, Rafinha and Franck Ribery are on the road to recovery from injury.
"No, no new players," he added. "Thiago will be back and Rafa will be back and Franck will be back so I am happy about this squad.
"Thiago will be back soon. He really wants to come back as soon as possible but for these issues we have a doctor and you should ask him."
