The 20-year-old was heavily linked with a move to Manchester United last summer, and despite a slow start to the season, he has started to get back to his best since the turn of the year.
"Jadon is doing really well at the moment, he's back. But that was only a matter of time. All the transfer talk in the summer has already been forgotten.
"Edin [Terzic] talked to him a lot. Jadon has shown again in the last few weeks what incredible quality he is. We are very happy that he is playing for us."
goal of securing a top-four finish in the German top flight, Watzke said:
"Of course, qualifying for the Champions League is still realistic. That is our stated goal. There are six points [for us to make up] on Frankfurt and Wolfsburg.
"In the end, we have to leave one of those two teams behind. It is certainly good that we have still got to play both of those teams. So, for us, everything is still possible."