The 24-year-old Poland star missed out on a move to European champions and domestic rivals Bayern Munich and will remain at the Westfalenstadion for the final year of his contract.
But Lewandowski, who notched 24 Bundesliga goals last term and netted a further 10 during Dortmund's run to the Champions League final, is adamant he will be as focused as ever on the pitch.
Speaking after landing the German Super Cup with a 4-2 win over Bayern, he told Bild: "I hope this is not the last title.
"I will give everything I've got for Dortmund. It does not matter what happened. I am not interested about that on the pitch.
"When I am out on the pitch, then Dortmund is all I think about. I want to give it all I've got and be successful."