Story highlights Tiger Woods still unsure when he will return

Says he can still beat Jack Nicklaus' record of 18 major titles

(CNN) He still thinks he can pass Jack Nicklaus as the most successful golfer ever, but Tiger Woods has no idea when he will return to competitive action.

The 14-time major champion maintains he is "progressing nicely" after a third back operation in October, but says he won't resume his career until he can practice, play and recover with no ill effects.

And despite not having won a major since 2008, the 40-year-old still believes he can overhaul Nicklaus' record of 18 major titles. The "Golden Bear" won his final three majors past the age of 40, including his famous 1986 Masters title as a 46-year-old.

"I think his major championship record is certainly still attainable," Woods told reporters at a media day for the PGA Tour's Quicken Loans National tournament that he hosts at Congressional Country Club in Maryland.

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