Sheboygan, Wisconsin: When Rory McIlroy won the PGA Championship a year ago, he was already the runaway favourite to dominate golf in the post-Tiger era.

He was just 25, with four majors already under his belt, and barely two weeks into a stretch at No. 1 in the world ranking that continues today. You were hard-pressed to pick out even one real contender on the horizon.

Then came the spring and summer of Jordan Spieth.

“He’s taking up a lot of the limelight this year, which is deservedly so,” McIlroy said Wednesday. “I mean, it’s one of the best years of golf that we have seen in a long, long time.”

McIlroy should know, since he had a front-row seat as Spieth won the Masters and US Open, then was sidelined by a bum ankle and forced to watch from the couch as Spieth nearly made it three majors in a row before faltering at the end of the British Open. And if nothing else, it enabled the 22-year-old Texan to cut even deeper into McIlroy’s lead. The last time the game had two players at the top with this much distance on the rest of the field was 1999, when David Duval mounted a brief challenge to Woods’ throne but lost his way soon after.

Because golfers wear gloves to grip the club — not throw punches — skirmishes between Nos 1 and 2 tend to be polite affairs. And so McIlroy, back after a 53-day layoff due to a ruptured ligament he suffered in a pickup soccer game with friends, threw nothing at his Texas rival but compliments.

“I think the performances that he put in at the Masters and the US Open and even at St Andrews when he was so close, you know, they were inspirational performances,” he said. “That’s something really for him to be proud of.

“Even though I’m not that much older, I think if I was — he was 21 at that point — I probably wouldn’t have handled it quite as well as he did.”

But rewind the tape to last May, when McIlroy was coming off a World Golf Championship title and Spieth’s impressive win at Augusta marked him as only one potential contender among many. Back then, McIlroy was asked whether all the attention Spieth was getting “gets your (competitive) juices flowing?”

“Not really,” he replied. “Last year, it was Rickie (Fowler), this year it’s Jordan, might be someone else ... There’s been four or five rivalries over the past year,” McIlroy added a moment later to laughter. “It’s really doesn’t do anything for me.”

Anyone looking to spark a feud between them soon realised they were leaving empty-handed on this day.

Spieth had a chance to unseat McIlroy last week and couldn’t seal the deal. He also hasn’t made the cut at his two previous PGA Championship appearances, and he’s a modest sort to begin with. So the most boastful thing he managed all day was acknowledging that he set a goal of being No 1 in the world at some point in his career and that he’d prefer it “to be sooner rather than later and then be able to hold onto it.”

With so little back-and-forth, someone finally asked McIlroy flat-out, “Regardless of rank, just from your perspective, who is the best player in the world?”

McIlroy stifled a smile. Then he got diplomatic. He said Spieth would deserve the title this year, but extend the time frame back two years and “it’s probably a toss-up.” Then he got even more diplomatic, saying it depends what part of the game you value most.

“So,” McIlroy said, “it’s all a matter of opinion at this point.”

Not to be deterred, the questioner asked a follow-up.

“Your opinion?”

“I’ll tell you at the end of the week,” McIlroy said with a wide smile.