Bayern Munich midfielder Bastian Schweinsteiger has apologised after a video of him singing a derogatory song about Bundesliga rivals Borussia Dortmund was published on the internet.
Bayern and BVB have gone toe-to-toe in the German top flight in recent seasons, sharing the last four titles between them -- and that has fostered a fierce rivalry among both fans and officials.
Although he won the World Cup alongside Dortmund stars such as Mats Hummels and Kevin Grosskreutz, Schweinsteiger, 29, was captured on film joining in with a fans' chant that refers to Bayern's rivals as "sons of bitches."
"I have broken off my holiday because it has come to my attention that a video with me in it has been spread around the internet," the Bayern midfielder wrote on Facebook. "I would like to apologise to the fans, officials and players of Borussia Dortmund.
"I don't want to gloss over anything. It is a well-known supporters' chant, but I didn't want to offend anyone with that swear word."
Schweinsteiger stressed that he got on well with all the Dortmund players, particularly Grosskreutz, who lent his international teammate his support on his Instagram account.
Grosskreutz wrote: "Hey Schweini! That wasn't cool, but I understand your explanation with regard to this and I will never forget everything that you have done for me! Everyone makes mistakes, and that should be the end of this!"
Dortmund later added a post on their Facebook page, which read: "Dear Bastian Schweinsteiger,
"That you, after clinching the World Cup (for which we send our heartfelt congratulations!), have an odd Weissbier, let your emotions out and you sing one or two rash remarks -- that's fair enough, not a problem! We have always regarded you as a fair sportsman and would never have made a meal out of your songs, while we -- of course -- accept your video apologies. We wish you a nice holiday still in Croatia!
"PS: You can put bent things straight. If you ever need any singing lessons, just let us know. We'd be happy to help you."