But for Rory McIlroy it’s his own unshakable self-belief that makes his the favourite to capture his fifth major here this week.
The 28-year old might be the world number four, winless since last year’s Tour Championship and bereft of the limelight now that Spieth has a chance this week to beat him to the career Grand Slam.
Given the Co Down man’s poor starts in the majors this year — he shot 72-73 at Augusta, blew up with an opening 78 in the US Open, and then soared to five over after six holes in The Open — it might appear that his desire to end that three-year major drought is getting to him.
Far from it, McIlroy insisted yesterday.
After a season curtailed by a rib injury and a complete change of equipment and golf ball, he comes to a venue where he has two wins and four top tens from seven starts insisting he has no sense of urgency, just a desire to play his normal game.
“I definitely don’t want to be in the mindset this week of wanting to make any type of statement or go out and prove myself,” McIlroy said.
“I’m past that point. I’ve proven myself enough over the last nine years of my career.
“Obviously I wouldn’t have won as much as I would have liked this year, and there’s been a few components to that, injury-wise, changing equipment and stuff. It has been a bit of a transitional year.
“But I feel like everything’s settled and my health is pretty much where it needs to be. So no, I just want to go out there and play well this week.
“It’s a golf course I’ve played well on before. But I’m definitely not going out there to try to prove anything to anyone. I just want to go out and play my game, and hopefully, that will be good enough.”
Just two and a half years ago, McIlroy went to Augusta National hoping to win the 2015 Masters and complete the career Grand Slam. Instead, victory went to a 21-year old Spieth, who is now just one major away from beating McIlroy to the punch.
While he was a 20-1 shot for The Open, McIlroy is the 7-1 favourite this week following his share of fourth behind Spieth at Royal Birkdale and his tie for fourth after a driving exhibition in the WGC-Bridgestone Invitational in Akron.
“I told you those odds wouldn’t last long,” McIlroy joked last night.
“My form is better coming into this event than it was going into the Open obviously coming off the back of a couple of missed cuts. I’m coming off the back of a couple of top fives; things are a bit different than they were a couple of weeks ago.”
McIlroy has huge admiration for Spieth, lauding the 24-year-old Texan’s ability to pull off wins when all looks lost.
“He has got that knack,” he said. “I call it resilience. I don’t know if there’s a better word to describe what it is that he has.
“But he has got this resilience where he gets himself in positions in tournaments where you don’t think he can come back from, and he does. It’s awfully impressive.
“It’s a mental thing. You can stand and hit the shots that he was hitting for those last five holes at The Open on the range, no problem.
“But being able to do it under those circumstances, under the pressure, that’s what makes him so good, being in those situations.
“Resilience, mentally tough, strong, whatever you want to call it. That’s his biggest asset. Being able to forget about a bad shot and move on to the next one, that’s his greatest weapon.”
McIlroy was too modest to single out his own greatest asset but having come back from slumps several times in his career already, he admitted that his self-belief is what gives him most confidence.
“I’ve never lost faith,” he said when asked his greatest strength. “I think my belief. I have always believed in my own ability from day one. And I still do.”
When Spieth won the Masters in 2015, McIlroy reacted by winning the WGC-Cadillac Matchplay before going on to win at Quail Hollow for the second time, shooting a course-record equalling 61 en route to a seven-shot win.
He said back then that he wanted to make a statement to the world and prove he was the true world No 1.
While much has been said in the build up about his erratic wedge play, McIlroy decided after his first practice round to take out his 52-degree wedge and put in a three-iron on a 7,600-yard course that’s playing longer than ever following a course redesign and recent heavy rains.
“Short irons and wedges are the big thing I have been focussing on but in saying that, the golf course is playing so long I don’t think we are going to have many short irons and wedges this week,” McIlroy said on his decision to go from four wedges to three.
“I changed yesterday when I saw I needed the three-iron in the bag for that sixth hole (249 yards), which is a long par-three.
“I played 18 holes yesterday, and I hit seven-iron on the first, eight-iron on the second, seven-iron on the third, six-iron on the fourth, eight-iron on the fifth.
“So there are really no wedges there and on the longer holes, you are hitting three and four irons.”