World number one Tiger Woods says his recovery from back surgery has been a "very slow process" and he remains unsure over when he can return to competitive golf.
Woods, who has won 14 majors, has been sidelined since going under the knife for a pinched nerve in his back at the end of March, forcing him to miss last month's Masters tournament for the first time in 20 years.
"I made the decision to have surgery because physically I just couldn't make a golf swing. That pretty much sums it up," Woods wrote in a blog on his website.
"Some people heal up in three months, some people take four, some people take longer.
"As for my return to golf, I really don't know. I'm doing everything I can and listening to my doctors."
The slow recovery could also force Woods to sit out the US Open at Pinehurst, which begins on June 12, and the British Open at Royal Liverpool in July, denying him a chance to end his six-year major drought anytime soon.
"I haven't used a sand wedge yet. I've just done putting and chip-and-runs using the same length of motion. I haven't really rotated yet," Woods, who is second only to Jack Nicklaus (18) on the list of major winners, continued
"As far as taking a full swing, I have conference calls with my doctors every couple of weeks to see how my progress is and just kind of chart it out from there.
"As I've said several times, I hope to be back sometime this summer, but I just don't know when."