That came just days after news emerged of a bizarre incident in his home city of Copenhagen where he was branded "arrogant" for his reaction after a credit card was declined in a pizza takeaway.
Full text of Nicklas Bendtner's open apology letter to Sunderland:
"Dear friends, fans, Sunderland and family.
"The past couple of weeks have seen me involved in several incidents that have attracted much negative attention from the media.
"After the friendly international versus Finland I was part of an unfortunate incident at the team hotel where I more or less was portrayed as a violent character. Anybody who knows me can testify that I am not. Police in the end decided not to press charges.
"In connection with a birthday celebration with my girlfriend I was part of an incident at a pizzeria in downtown Copenhagen where my credit card got rejected. I bet you all know the feeling but in this case it was also described in the media.
"The latest incident involves two of my team-mates and me who were picked up by polite and friendly English policemen this morning as CCTV footage allegedly shows us in the process of damaging parked cars after a wet night out on the town.
"This case now has to make its way through the British system of justice and a verdict is expected by February next year. In connection with all these incidents I have to make one thing very, very clear.
"I am extremely sorry for all of this. I apologise sincerely that I have allowed myself to get involved in things that are interpreted in such dramatic fashion. I fully assume responsibility for not distancing myself from these incidents before they got out of hand.
"The error is mine alone and I am sorry that I have let so many people down. Basically I am a normal guy with an extraordinary job.
"I tend to forget this at times but deep down I know these things. And it does not serve as an excuse for me letting myself get caught up in this.
"My family, my son, my precious girlfriend and football are the most important things in my life. And this is what I will have to focus on 100 per cent.
"My primary objective right now is to get rid of my injury and get back into full fitness for Sunderland and Denmark. I hope you will understand that I now promise to concentrate fully on football and only football. My focus has to be here - and not anywhere else.
"It means that I in the upcoming time won't be involved in extracurricular activities - like too many parties or interviews about my persona. Trust takes time to build - and I now can see how quickly it disappears.
"I admit my sense of judgement has been less than perfect lately. Going forward I will do all I can do in order to honour the trust that you, my fans, my friends and my lovely family show me every single day. Nothing short of the best is good enough for you and it is something I haven't produced for you lately.
"See you - on the pitch. Warm greetings, Nicklas."
LOCK THE MACKEM BASTARD UP!