The Spaniard believes "anything can happen" when the Bavarian club visit the SGL Arena on Wednesday, while winger Arjen Robben also predicts a difficult game
The Allianz Arena side qualified for the inter-continental tournament, which takes place later this month, having won the Champions League last season.
But Guardiola, whose team won the domestic cup competition last term to cap off their treble-winning campaign, thinks that the last-16 tie with Augsburg is the biggest game left in 2013 for the club.
"We still have the Club World Cup but, for me, this is the most important game before the winter break," he told the club's official website. "It's like a final!
"The DFB-Pokal can be very dangerous. It's just a game and anything can happen, especially against a team like Augsburg.
"They're a very combative and strong team physically, they're great on the counter-attack too."
Bayern winger Arjen Robben agrees with Guardiola's assessment that their fellow Bundesliga side could pose a serious threat to their potential progress into the quarter-final stage for the 11th time in 12 campaigns.
"Augsburg have played a solid season so far," he said. "Plus, they're playing at home. This will be a difficult game."
The clash at the SGL Arena kicks off at 19:30 BST, and will be followed by league clashes against Werder Bremen and Hamburg before Bayern jet off to Morocco for the Club World Cup.