**Sinner's withdrawal with a right knee injury has opened the men's draw significantly at the 2026 US Open, shifting the top seed to Zverev and elevating Alcaraz (returning after four months out with a right wrist issue) and Djokovic in seeding.** Alcaraz's lack of recent match play creates uncertainty around his early-round durability on hard courts despite his defending-champion pedigree, while Zverev enters with strong recent form including a Roland Garros title. American players like Shelton and Fritz benefit from solid summer hardcourt results, and mid-tier contenders such as Fils, Cobolli, and Medvedev gain realistic quarterfinal paths in a less stacked field. Trader sentiment reflects these fitness and form variables, with the absence of the dominant world No. 1 increasing upset potential through the round of 16.