Might a McIlroy-Spieth rivalry begin to brew?

— -- HAVEN, Wis. -- Rory McIlroy decided to have some fun at the golf world's expense last week, issuing hints via social media that he was poised for a return to competitive golf after what many believed was a devastating ankle injury.

Speaking in emoji while posting a photo from inside a private jet bound from Europe to the United States was also a nice touch, if not an outright taunt.

Then there was Jordan Spieth, sticking it to Phil Mickelson by playfully suggesting that he'd bring his U.S. Open trophy to Whistling Straits to show off during their Tuesday practice-round match, payback for all the ribbing and hazing he has received from the five-time major champion who is missing that one title.

Call it the new age of good-natured fun or eyebrow-raising bravado, but it's certainly not from the Tiger Woods textbook of preparing for a major championship.

The 1-2 showdown from the world rankings that many envisioned after Spieth won the Masters and U.S. Open this year will finally materialize this week on the shores of Lake Michigan during the fourth and final major championship of the year.

At least there is hope for such a duel as they are grouped for the first two rounds of the PGA Championship along with Zach Johnson, who won The Open at St. Andrews last month.

Such hype is often misplaced in golf, given the rare encounters between the top players, and the even rarer times they go head to head down the stretch in a major championship. But we can dream at the PGA, which begins Thursday morning.

It all was supposed to happen last month at St. Andrews, where Spieth was bidding for the third leg of the Grand Slam and McIlroy was the defending champion of The Open. The two players held all four major championship trophies between them at the time.

That storyline was obliterated July 4 on a Northern Ireland soccer pitch, where McIlroy ruptured the ligaments in his left ankle while -- as he said he had done several times in previous days -- partaking in a "kick-about'' with friends.

McIlroy, 26, was unable to defend his title at the Home of Golf, leaving the stage to Spieth, who hardly disappointed in his attempt to become the only player other than Ben Hogan to win the Masters, U.S. Open and The Open in the same year.

Spieth came up a shot short of a playoff won by Johnson, with McIlroy forced to watch from his couch in a walking boot.

It led some to wonder if McIlroy was itching to get back sooner than necessary, if the focus shifting might be having an impact. After all, it was McIlroy who surged to No. 1 last year after winning consecutive majors with a World Golf Championship title as well.

"I'm not surprised at all that the narrative has gone from me to Jordan and to both of us being here,'' McIlroy said. "Jordan has played phenomenal golf for the last 12 months. And even to win the first two majors of the year, have a great chance at St. Andrews, he's taking up a lot of the limelight this year, which is deservedly so. It's one of the best years of golf that we have seen in a long, long time.

"I guess as well, we live in such a world that everything's so reactionary and everything happens so quickly that a year ago after I won this tournament, it was the Rory era. And then Jordan wins the Masters, and it's the Jordan era. And eras last about six months these days instead of 20 years. But it's just the way the world is, with social media and everything having to be instant. It's the world that we live in.''

Spieth, 22, is familiar with that world. While McIlroy was rattling off those impressive victories last year, working his way back to No. 1 (he had been there in 2012 and 2013), Spieth kept hearing the whispers that he couldn't close tournaments.

Never mind that had he stayed at the University of Texas, Spieth would have still had a year of school to go. But he turned pro in 2012, won the John Deere Classic at age 19 in 2013, then had near-misses at the Masters and Players Championship in 2014. In each case, a final-day lead did not hold up.

As the summer waned, Spieth's results suffered. A year ago he missed the cut at the PGA Championship and ranked as low as 14th in the world.

But a victory at the Australian Open in November was the difference. He shot a final-round 63 to win, then won Woods' Hero World Challenge a week later. He got his second PGA Tour title at the Valspar Championship in March, lost in a playoff at the Shell Houston, then won the Masters.

Since a little lull following his victory at Augusta National, Spieth has been third at the Memorial, won the U.S. Open, won the John Deere, finished a shot out of playoff at The Open where he tied for fourth and tied for 10th last week at the WGC-Bridgestone.

And now comes the chance to go head-to-head with McIlroy, albeit in the opening rounds.

"I think that's just what you guys want to see,'' Spieth said. "I think he and I just want to go out there and try and win the tournament. I mean, we have to beat each other in order to do that, along with 155 other guys. It's great. We're all very happy to see him back.''

Spieth is trying to become the first player to sweep the American-based majors in the same year and just the third -- joining Ben Hogan and Woods -- to win three in the same season.

He also has another goal: making the cut.

At the beginning of the year, Spieth had a goal to make the cut in all four majors and to contend in at least one of them. He has handled that latter part pretty well.

He also has a chance to fulfill another goal, one that he didn't envision being possible at this point: No. 1 in the world. He'll need to finish at least third and, depending how McIlroy fares, it would happen in a storybook season.

"I did not have a time frame,'' Spieth said of the goal to get to No. 1. "When that was a goal that was just a career goal at one point in my career. Given everything that's happened, I believe now that I would like it obviously to be sooner rather than later and then to be able to hold onto it.

"That's a whole other animal, as I'm sure Rory knows, Adam Scott knows, Luke Donald knows, there's Tiger, these guys that are in this field, Martin Kaymer, there's Vijay [Singh]. There's a number of them that understand what it's like. I don't know what that feels like yet. That will be a new goal, if I can accomplish the one prior at some point in my career.''

Can McIlroy and Spieth go head-to-head over the weekend? Such duels are rare in major championships, the Tom Watson- Jack Nicklaus "Duel in the Sun'' at Turnberry a notable exception.

For example: Woods and Mickelson were paired in the final group just once during a major that either player won: the 2002 U.S. Open at Bethpage, where Woods triumphed.

So far this year, McIlroy has three victories: a European Tour title in Dubai, as well as the WGC-Match Play and the Wells Fargo Championship. He finished in the top 10 at the Masters and U.S. Open.

Spieth has won four times, including the two majors. He also has 12 top-10 finishes.

Most observers agree that when McIlroy is at his best, he's a notch or two ahead of Spieth. But there's no denying the younger golfer's resolve, his desire to get better and maximize his strengths.

Spieth acknowledges McIlroy's length off the tee and said, "I certainly envy that. There's not much I can do about it right now except try to hit my approaches even closer and make a few more putts. But yeah, Rory's an inspiring player.''

For his part, McIlroy, too, has taken inspiration from Spieth's success this year. "It's something to really be proud of, especially how he handled everything at St. Andrews going into all the Grand Slam talk. He handled that so well. I'm not that much older -- he was just 21 -- but I probably wouldn't have handled it quite as well as he did.

"It gives me some motivation to go out and try to play even better.''

Neither player is shy on social media. Both are well-spoken and thoughtful in interviews. They come from different parts of the world, but seemingly give the game a bright future. Can they sustain a rivalry? Can they even start one?

Whistling Straits and the PGA Championship should begin to provide some answers.