Having signed 12 months ago from Cologne, the German international went on to score 16 goals in all competitions last campaign.
However, despite admitting that he is pleased with his contribution, the 28-year-old is eager to add even more to the team over the coming months.
"Last season was a good season for me. I scored a lot of goals and made a lots of assists so I was happy," he told The Sun.
"I came from a small team like Cologne so it was not easy but, hopefully, this year will be better."