Jannik Sinner's right knee injury is drawing serious concern from analysts ahead of the US Open, with former British No. 1 Greg Rusedski going on record to say the situation is worse than the Italian has let on publicly.

Sinner, a five-time Grand Slam champion, had already withdrawn from the Canadian Open before confirming he would also skip the Cincinnati Masters. In his own statement, Sinner acknowledged the knee has been "bothering" him and that, despite intensive work with his medical team, he is not yet ready to compete. He confirmed his focus is now entirely on being fit for New York.

For Rusedski, that timeline is a red flag. Speaking on his Off Court podcast, the former world No. 4 pointed out that skipping both North American hardcourt events leaves Sinner without any competitive preparation heading into the year's final Grand Slam. "It's concerning because he always plays a lead-up," Rusedski noted, adding that arriving without match practice raises genuine questions about his readiness to defend.

Rusedski also floated an alarming scenario: if both Sinner and Carlos Alcaraz miss the US Open, the draw becomes dramatically more open. He highlighted Novak Djokovic, chasing a 25th major title, and Alexander Zverev, hungry for a second, as the players who would benefit most. Rusedski also pointed to Ben Shelton's stunning Canadian Open title run, where the American did not drop a single set, as further evidence of a growing competitive field.

Perhaps most pointedly, Rusedski suggested Sinner has already shown he is "beatable" this year in non-Masters events, adding another layer of uncertainty.

TennisDraw users will be watching Sinner's fitness updates closely before locking in their US Open bracket picks.