Alexander Zverev’s former coach David Ferrer believes that the Olympic champion can return to his form of the past once he returns from a long injury lay-off and finally aim to win a grand slam title. Zverev, 25, has not played since rupturing ankle ligaments at the French Open in early June but plans to play his first matches in December at exhibition tournaments before re-joining the tour. Ferrer, who coached the German for a while in 2020, told dpa that Zeverv “will play an important role again” when he returns. “It is always difficult after such a long break, especially at the start. But t…