MONACO - Jannik Sinner will not compete in the 2026 US Open. The world number one has officially withdrawn from the final Grand Slam tournament of the season due to a right knee injury that continues to hinder his preparation. The ATP Tour decision came after treatment and tests in recent weeks and an attempt to return to on-court training in Monte Carlo. Sinner and his staff preferred not to take any risks and to allow more time for recovery. Sinner: "A difficult decision." "Even though I worked hard with my team and my personal doctor, we…