The Spaniard has 18 months left on his deal at the Allianz Arena after joining the Bavarians following their treble-winning 2012-13 campaign under Jupp Heynckes.
However, Rummenigge insisted last week that Bayern were in no hurry to open negotiations with Guardiola, who guided Bayern to success in the Bundesliga, DFB-Pokal, UEFA Super Cup and the FIFA Club World Cup in his first season in charge.
Despite being prepared to hold off on entering talks, Rummenigge insists Bayern have not contemplated what might happen if Guardiola elects to make an exit.
"There is only a Plan A, and that means Guardiola," he told Kicker.
"If he and his family feel at home, he remains. If not, we would have to deal with it in a relaxed way."
Bayern are 11 points clear of Wolfsburg at the top of the Bundesliga at the halfway point of the season.
