Tiger Woods will miss his second major championship of 2014 as he struggles to return to top form following back surgery earlier this year.
The 14-time major winner announced on his website on Wednesday that he is skipping next month's US Open while he continues his rehabilitation.
"Unfortunately, I won't be there because I'm not yet physically able to play competitive golf," Woods said.
"I'd like to convey my regrets to the USGA leadership, the volunteers and the fans that I won't be at Pinehurst."
"The US Open is very important to me, and I know it's going to be a great week. Despite missing the first two majors, and several other important tournaments, I remain very optimistic about this year and my future," he added.
Woods has not competed since the final round of the WGC-Cadillac Championship in March and this is the sixth major championship the American has missed because of injuries.
Woods shot a third round 66 at the WGC-Cadillac to vault back into contention but struggled with back pain in the final round on March 9. Three weeks later, he underwent microdiscectomy surgery to alleviate a pinched nerve in his back.
The 38-year-old also missed four months of the 2011 season with knee and Achilles injuries.
In 2008, Woods won the US Open at Torrey Pines golf course in San Diego while playing on a broken leg. He then underwent surgery that resulted in him being out for eight months and missing the PGA Championship and The Open Championship that season.
Last week, 2013 Masters winner Adam Scott surpassed Woods as the number one ranked player in the world. Woods is now the world number three behind Scott and Henrik Stenson.
Scott overtook Woods to claim the top spot for the first time, ending Woods' latest reign at 60 weeks. Woods enjoyed 281 consecutive weeks atop the rankings from 2005 to 2010.
Woods has slipped to third but is expected to fall more spots as he remains absent from the tour.
Woods told reporters earlier this month that there was no timetable for his return.
"That has been the real question through all this. There is no date," he said. "It's not up to me. It's not going to be up to me if I play. It's up to my doctors."