Carlos Alcaraz's wrist injury, which has kept the world No. 2 sidelined since withdrawing from the Barcelona Open in April, remains the dominant factor shaping the closely balanced 51% implied probability for his US Open participation. Recent withdrawal from the Cincinnati Masters 1000—his planned return event and a key hard-court warmup—has heightened concerns about full fitness ahead of the late-August major, where he is the defending champion and officially entered. With no competitive matches in over four months and a cautious recovery approach prioritizing long-term health over rushed preparation, traders reflect uncertainty around his ability to build match readiness. Positive medical clearance, increased hitting intensity, or a late entry into the Winston-Salem Open could strengthen the case for participation, while any further setbacks or official withdrawal would likely shift sentiment toward absence.