The quarterfinals are underway at Melbourne Park, as rumours abound about Jannik Sinner's health ahead of his clash with Alex de Minaur. Follow live.

As much as any top player, Sinner has been able to expose De Minaur’s lack of first-strike weaponry. The Aussie’s strength is his scrambling and counterpunching, but Sinner serves too well, hits too hard, places the ball too precisely for his defense to be effective. De Minaur hasn’t found a way to hurt, rattle, of disrupt him.