The absence of world No. 1 Jannik Sinner due to a right knee injury has significantly altered the men's singles draw at the 2026 US Open, elevating Alexander Zverev as the top seed while leaving defending champion Carlos Alcaraz to return from a four-month right-wrist layoff without any warm-up matches. Alcaraz's match fitness and stamina in best-of-five sets remain key variables, though his elite level could still propel him deep if he builds rhythm quickly on the hard courts. Recent hard-court form from players like Ben Shelton, Taylor Fritz, and Brandon Nakashima, combined with Novak Djokovic's experience and Arthur Fils' rising consistency, positions several contenders for semifinal berths amid an unusually open bracket. Draw positioning, potential fatigue from the schedule, and any late fitness concerns will heavily influence which players advance past the quarterfinals.