Rory McIlroy believes the golf world saw the best of Tiger Woods a decade ago and he will struggle to return to the top of the sport's rankings.
Woods, who has not won for two years, is now ranked 49th, his worst ranking since he was a novice in 1996.
The American's slide started with problems in his personal life before injuries also took their toll.
"We saw the best of Tiger in 2000 and 2001. I don't think golf can be played any better than that," said McIlroy.
"He didn't even need to play that well to win tournaments - he won the US Open by 15 shots, the Open by eight - so I think we've seen the best of him but that's not to say to he won't win again.
"But (getting back to number one) will be difficult for him because the fields are so much deeper.
"He set the benchmark and that's where we're all trying to get to. I don't think anybody has got there yet but we're getting closer.
"It will be a tough ask for him to get back there."
Woods has won a total of 14 majors, including eight since that 2000-2001 purple patch, but has not looked like adding to that total since his after nine months of lurid headlines about his private life.
Injuries have been his main worry since then but he has also endured a very public separation from his long-time caddie .
McIlroy's comments came on the day it was announced he has signed a sponsorship deal with European banking giant Santander, underlining his status as one of sport's most marketable names.
The Northern Irishman in June with a display that reminded many observers of Woods at his very best.
The manner of his victory - and affable personality - catapulted the 22-year-old into almost Tiger-like levels of fame. And his profile has risen even higher in recent months thanks to a budding romance with world tennis number one Caroline Wozniacki.
McIlroy, ranked third in the world, has only played six tournaments since his major win but back-to-back third-place finishes suggest his game is in reasonable shape as he prepares for next week's Alfred Dunhill Links Championship in Scotland.
His growing army of fans will be out in force for that, particularly as sightings on this side of the Atlantic might be less frequent in future. Last month he announced his intention to return to the US Tour only a year after deciding to give up his playing privileges on the world's richest circuit.
This U-turn has prompted some to speculate he is turning his back on European golf but McIlroy denies this, offering a far simpler explanation for his change of heart.
"My game is suited to the States. I just like to play over there, that's the main reason," he said.
"I'm a bit of a fair-weather golfer, even I'd admit that!
"My natural ball flight is more suited to those conditions than it is to the windy conditions you get in the UK or Ireland. So I'll have more of a chance playing in the sunshine."
McIlroy puts his preference for American-style golf down to his upbringing on a parkland course at Holywood Golf Club, as opposed to his compatriots Darren Clarke and Graeme McDowell who grew up on Royal Portrush's links.
"I also watched a lot of golf on TV and the way Tiger, Sergio (Garcia) and Ernie (Els) played was how I wanted to play the game. I tried to emulate them."
Emulating Tiger's pursuit of major victories is his next target.
"I want to give myself a good chance in all four majors," he said.
"If I was sat down here next year and hadn't won one I'd be disappointed. It would be an opportunity missed."