The Germany international has been a key part of the team since sealing a permanent move from Bayern Munich in 2009 following a successful loan spell at Signal Iduna Park.
And he says he is ready to take more responsibility as Jurgen Klopp's men look to wrestle back the Bundesliga title from the Bavarians.
|6/1||Borussia Dortmund are 6/1 with Coral to win the Bundesliga
"This means that I am not hiding in games. If I notice that somethng does not work in the team, then I change the situation for the better.
"You have to do this if you have played for the team for a long time as I have in recent years. And I will do it gladly."
The 24-year-old went on to admit that he was far from happy with his showings last term as he made a number of high-profile mistakes, most notably in the first leg of the Champions League semi-final against Real Madrid.
"I was not satisfied with my performances last term," he continued. "It was far below what I had envisioned and far below where I have to be. The number of blunders...
"These are things that are unbearable for me. Next season will be different. I'm taking every friendly, every training session, as seriously as a real game.
"At this level, there are many small factors that can make you play better or worse. A bad attitude has no place here.
"[I want to be] better than last season. Second place is okay, but there were many unnecessary defeats, many goals we should not have conceded."