Jordan Spieth is a fascinating psychological specimen.

To his everlasting credit, he doesn't seem to have a pause button from his brain to his mouth. He feels what he says and says what he feels, and we should all hope that never changes.

He told reporters Saturday night that he would have a difficult time getting over the double-bogey 6 he made on his final hole of the third round, even though he still was leading the Masters for the seventh-straight round.

“Probably go break something,” he admitted, with only enough of a smile that you thought he might not do it.

Spieth admitted Sunday evening, after he had blown a five-shot lead on the back nine to lose to Danny Willett, that he actually said to caddie Michael Greller, “Buddy, it seems like we're collapsing.”

That was the money quote, but what came after it was more interesting.

“I wanted to be brutally honest with the way I felt toward him,” Spieth said, “so that he could respond with what was necessary to get us to rebound. And we did. I rebounded.”

What Greller said, we have no idea. Maybe he didn't say anything. Just nodded and listened. Maybe he produced the greatest one-minute pep talk in history.

Remarkably, Spieth did respond, making birdies on the back-nine par-5s — 13 and 15 — to give himself the chance to make two more birdies in the last three holes to possibly tie Willett. He didn't do it, going par-bogey-par.

Willett shot 67 and beat Spieth and Lee Westwood by three shots.

Spieth shows bulldog resilience but also an indecision and lack of confidence at times that make him appear as not a dominant pro athlete but more what he really is — a 22-year-old still finding himself.

Greller is a former grade-school teacher, and at times it seems he's just trying to get Spieth to stay in his seat and look at the board.

He plays the role of brother, mentor and psychologist. He takes in Spieth's constant chatter and processes it as best he can. For one shot Sunday, Spieth could be heard on the microphone seeking assurance about a club selection. Greller gave him a strong affirmation. Spieth responded to the effect, “You really think so?”

It's comical, really, the banter and the psychological game that goes on between them. Spieth uses “we” all of the time, and it sounds great when things are going peachy, less so when they're not.

What Sunday proved is that Spieth still has a lot to learn about handling his thoughts and emotions, but he seems to understand that better than anybody.

Willett, who went to college at Jacksonville State in Alabama, is far from a household name in America because he has never played full time on the PGA Tour since turning pro in 2008. (He's planning to play full time here next season.)

But Willett had more than shown he possessed a game strong enough to win a major.

He was the world's No. 1-ranked amateur and played in the Walker Cup before turning pro. He had won four times on the European Tour and finished second to Rory McIlroy last year in the Race to Dubai

This season, he already had captured the Dubai Desert Classic and finished third in the WGC event at Doral.

Willett played in his first Masters last year because a late-season charge got him to 50th in the world — the last automatic qualifying spot.

Known for a strong work ethic, Willett said Sunday night that he believed he arrived at being the Masters winner by facing those parts of his game that needed polishing. He works with coaches Pete Cowen and Mike Walker.

“Every time you go to the range, you're not getting there to get a pat on the back and tell you how good you're doing,” he said. “You go there to try to try to get better, to try to get that half, that 1 percent better. … Actually trying to accomplish that perfection makes you uncomfortable.

“Today was one of them where I feel like I've done enough work and hit enough balls under their supervision; each shot that I was faced with, I just went through the same process and tried to remind myself of golf shots that I hit on the driving range when you're in practice.

“Fortunately enough, we came through.”

tod.leonard@tribpub.com