Agent: Tiger Woods staying course

— -- ORLANDO, Fla. -- Tiger Woods' back issues are due to a bulging disk that will not require surgery, according to Golfweek magazine, although the golfer's agent did not confirm the report.

A person with knowledge of the situation told Golfweek of the diagnosis but said it could have been worse because the issue is not a herniated disk, which could call for surgery.

"Nothing has changed since the announcement on Tuesday," Mark Steinberg, Woods' agent, said in an email Thursday. "He is resting and [we'll] evaluate in the coming days."

Woods withdrew from the Arnold Palmer Invitational, a tournament he has won eight times, with a Tuesday phone call to the tournament host. Woods said on his website that the pain from back spasms had yet to subside, hence his inability to play at Bay Hill.

"It's too early to know about the Masters, and I will continue to be evaluated and work closely with my doctors," Woods said in his statement.

Woods, ranked No. 1 in the world, has never missed the Masters since playing in his first one as a pro in 1997. He has won the tournament four times, but not since 2005.

In just four tournaments this year, Woods' best finish is a tie for 25th at the WGC-Cadillac Championship, where he shot a final-round 78 and was clearly bothered by his back.

Afterward, Woods said it was the same thing that affected him a week earlier when he withdrew from the Honda Classic during the final round.

Asked if the injury was more serious than back spasms, Woods said: "Well, it is back spasms, so we've done all the protocols and it's just a matter of keeping everything aligned so I don't go into that."

Asked if he has had an MRI performed, he replied: "As I said, we've done all the protocols."

Woods had back spasms at the Barclays last August and the back problems bothered him for the rest of the FedEx Cup playoffs. After rest, he tied for third at a European Tour event in Turkey and lost in a playoff at the World Challenge prior to a lengthy break before resuming his schedule in 2014.

In his first two rounds at Torrey Pines and in Dubai, Woods did not appear to have any back trouble. It didn't become an issue, he said, until warming up prior to the final round of the Honda Classic on March 2.

Woods was not expected to enter any other tournaments prior to the Masters, which begins April 10.