# Tennis: World number one Jannik Sinner is teaming up once again with Umberto Ferrara, the fitness coach he sacked in the summer of 2024 after it was revealed that the Italian had tested positive for doping. Since the revelation of Sinner’s positive tests for the anabolic steroid clostebol, Sinner has constantly maintained his innocence, laying the blame squarely on his team. Sinner dismissed Ferrara and his physiotherapist, Giacomo Naldi, after the revelation of his positive tests.
Tennis: Sinner re-hires fitness coach he fired after testing positive for banned substance