Jannik Sinner has rehired Umberto Ferrara as his fitness coach, reversing his decision to dismiss him following a doping case where Sinner served a three-month ban after testing positive for Clostebol.source https://timesofindia.indiatimes.com/sports/tennis/tennis-jannik-sinner-re-appoints-former-fitness-coach-a-year-after-doping-ban/articleshow/122855471.cms