The 43-year-old urges his side to be on their mettle in the DFB-Pokal first round on Sunday and calls on his players to show mental strength to compensate for injuries
Bayern begin the defence of the trophy with a trip to third-tier Preussen Munster on Sunday but the coach insists that their opponents represent a perilous step up in class from amateur outfit BSV SW Rehden, whom 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 told reporters.
"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 and 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 absent stars.
"We have to deal with the situation as we find it," he declared. "All we can do is compensate over the next few weeks with mental strength and passion but I'm confident it'll work out."