Bayern Munich chairman Karl-Heinz Rummenigge slammed Borussia Dortmund fans for their "ingratitude" towards Mats Hummels during the DFL-Supercup on Sunday.
Hummels made his competitive debut for Bayern in their 2-0 victory over his old club, with goals from Arturo Vidal and Thomas Muller sealing the win for the Bundesliga champions.
"Ingratitude is the world's wage," he said. "It's a disaster that someone who gave everything for the club for years is booed like that - it's so disappointing."
Hummels admitted that it was a peculiar sensation to step onto the pitch as part of Dortmund's opposition, but said there are plenty of fans who remember him more fondly.
"I was caught out when I felt so emotional before my entrance into the stadium. It was a strange situation," he said, as quoted by Bild.
"You can treat the subject as you wish. There are also a lot of very positive things still. I still see people write on Twitter and Facebook, who value our time together. To them, I try to respond to say that I see it that way."
"It is the first title but my performance could be better," he said. "But if, after only eight days of training, you were at the same level as those with five weeks of training, then pre-season would be nonsense.
"For me, it was an important game to make a step forward concerning my fitness. Regarding my performance, that was hopefully not the top limit."
