Jannik Sinner’s decision to reappoint Umberto Ferrara as his fitness coach raises major questions about judgment and principles. It gives conflicting messages about responsibility and trust when the world’s No.

World number one Jannik Sinner reappoints fitness coach Umberto Ferrara less than a year after they parted company.

Jannik Sinner has reappointed fitness coach Umberto Ferrara to his coaching team having previously dropped Ferrara during Sinner’s recent doping suspension.