The former Bayern coach says that the Catalan, who will replace Jupp Heynckes at the end of the season, would face "enormous" expectations at the Allianz Arena.
"FC Bayern have hired a top man," he told German daily Die Welt. "But expectations will be enormous.
"This can also turn out to be a problem, if expectations are fuelled, which, as they are too high, he has to fall short of.
"When I say Bayern play better than ever before: How could Guardiola make them better? And just imagine Jupp Heynckes is to win three titles. There'd be none left for Guardiola."
Bayern are currently 17 points clear at the top of the Bundesliga table.