Real Madrid thrashed Bayern 4-0 on Tuesday to complete a 5-0 aggregate victory, ending the reigning champions' bid for back-to-back European Cups.
Bayern looked out of sorts in Munich and simply could not match Real, which has prompted widespread criticism of the approach of coach Pep Guardiola, but Rummenigge hit out at the critics on Friday.
"It's sickening how this team and its manager have been treated," the 58-year-old was quoted as saying by Spanish newspaper Marca.
"We haven't lost against any old team. These things can happen. It's not a catastrophe."
Rummenigge reiterated his belief in Guardiola's tactics, with the former Barcelona coach having turned Bayern into a team that dominates possession - just like the Catalan club did courtesy of Lionel Messi and Xavi - in just one season.
"Pep is a very successful manager and a great person. We must be happy that he is with us," Rummenigge said.
Bayern have already wrapped up this season's Bundesliga title and could win the DFB Pokal, if they overcome Borussia Dortmund in Berlin on May 17.
