According to French outlet MediaFoot, the Bundesliga side views Martinelli as a suitable option to fill the void left by Diomande. Playing time is cited as a major factor, as the 24-year-old alternates between starting and coming off the bench despite impressing in the Champions League with six goals.
Other European clubs are also monitoring the situation, with Atletico Madrid and Paris Saint-Germain reportedly inquiring about the Arsenal forward.