Rory McIlroy's third reign as world number one could last just a week after another missed cut in the Players Championship.
The 23-year-old's third trip to Sawgrass ended in his third early exit - and that opened the door to Luke Donald and Lee Westwood.
"There's something about this course I can't quite get to grips with," said the Northern Irishman after his second-round 76. "It's disappointing - I'm not going to lie. I've been playing well for the last 12 months. This is my first missed cut for a year."
He added: "I'll get ready now for the big tournaments coming up."
Having decided not to play the Volvo World Match Play in Spain, next up is the BMW PGA Championship at Wentworth starting on Thursday week. His US Open defence is little more than a month away.
He vowed to return next May to try again - last year he skipped the event - but said: "I'm a visual player and I struggle to see the tee shots required here."
It was his first missed cut since last season's Wells Fargo Championship and since August he had only twice failed to finish in the top five at any tournament.
A top-four finish would take Donald back to the top of the rankings, while Westwood needs a win. They are both three under at halfway.
Irish interest in the event is already over. Padraig Harrington and Graeme McDowell missed out by one on one over.