The Germany international only joined Werder in August, but has been outstanding in a struggling team.
There is talk of Gnabry's deal carrying an €8 million buyout clause and that he could be on the move again this year.
"For my future, I've decided to focus on how I play now and today. That's why I'm trying to concentrate on the now," the 21-year-old said.
"As of today, I do not intend to change in the summer. But what happens in the future depends on my performance. What if Chelsea or Arsenal come knocking? Well, at the moment I'm trying to give everything to Werder."