When Rory McIlroy won four majors in a little over three years, talk of his ascent to greatness was as inevitable as it was premature.

But in a sport where longevity means still playing well into your forties, and even beyond, you cannot be said to have scaled that particular mountain when you are 25, as McIlroy was when he last won a major.

That was the 2014 US PGA Championship and it came hot on the heels of his triumph at The Open.

That was when a new era appeared to be dawning in the world of golf, a post-Tiger age in which McIlroy was to be the star of the show.

In the five years since then, McIlroy has not added to his tally as he heads back to the US PGA. If 2014 did indeed mark the start of a new era, it cannot by any logical measure be described as McIlroy's.

Since then, Jordan Spieth and Brooks Koepka have claimed three majors apiece and Woods has returned to the winner's circle, adding a fifth Masters title to his collection in April.

Woods stands as the ultimate benchmark for greatness in the modern game, but in some ways he also serves as a cautionary tale for McIlroy, who turned 30 this month.

For Woods, that was the decade in which his decline – considered as terminal by some until a remarkable revival capped by his Augusta heroics – set in.

Injuries and personal issues took their toll, meaning Woods' thirties, when many golfers reach their peak, were largely squandered.

He was 32 when major number 14 arrived at the 2008 U.S. Open, but his latest green jacket ended an 11-year barren spell. If McIlroy does not win one of the three remaining headline events this year, he will be halfway to equalling that winless streak.

McIlroy's Valhalla victory in the 96th US PGA Championship gave life to the idea that he was destined to fulfil his immense promise and ultimately take his place among the sport's legends.

But as the years have ticked by, that goal has only seemed to slip further from his reach. McIlroy is doubtless very good, but is he great?

The Grand Slam remains elusive, he has not been year-end world number one since 2015, and there seems to be a lack of killer instinct when it comes to the crunch in major championships.

Bethpage will be a tough place for McIlroy to address his major jitters, but it would be the perfect time to do it.

While life may not begin at 30 for McIlroy, the path to sporting immortality might.