Shinji Kagawa has said he is "half unsatisfied" with his debut season at Manchester United - despite winning a third successive title.
The Japan international won back-to-back Bundesliga titles in his two seasons at Borussia Dortmund before moving to Old Trafford last year and helping United become champions of England for a record 20th time.
But the 24-year-old, who scored 29 goals in his two years at Dortmund, only struck six times for United and believes his own contribution could have been greater.
"It was great to win the title with United and to make it three in a row for me personally," he told Inside United. "But I feel I still have work to do. I would say I am half satisfied and half unsatisfied."
Kagawa aims to make more of an impact in the forthcoming season, adding: "I want to be a better player year by year. I expect a lot of myself. I hope to show my dynamism, style and presence more."
The key, he said, is "hard work", adding: "I think it is very important to keep working in your everyday training and in matches. You just have to keep practising. But you must also have a strong will. That is the key to playing in a foreign country, especially for me in Europe."