The 43-year-old has urged his side to be on their mettle in the DFB-Pokal first round on Sunday and has called on his players to show mental strength to compensate for injuries
Bayern begin the defence of the trophy with a trip to minnows Preussen Munster on Sunday, but their head coach insists their opponents represent a perilous step-up in class from amateur outfit BSV SW Rehden - the side they faced at the same stage last year.
"Anything can happen in the cup. If we think simply being Bayern Munich will be enough, it could be dangerous," he said.
"Now we face a third division team and they're all professionals. They have superb fans. It'll be a great atmosphere.
"We need time, but you don't get time in this competition. It's either in or out."
Bayern make Sunday's trip without a host of key individuals, including Bastian Schweinsteiger, Franck Ribery, Thiago, Rafinha. Midfielder Javi Martinez is also missing after suffering a cruciate ligament injury in the DFL-Supercup defeat to Borussia Dortmund.
And Guardiola has called on his squad to show the mental fortitude required to compensate for their missing stars.
"We have to deal with the situation as we find it. All we can do is compensate over the next few weeks with mental strength and passion. But I'm confident it'll work out."