When Justin Thomas won the 2017 FedEx Cup he was just about as unhappy as a dude could be who just earned $10 million. Because, it seems, he’s a bit OCD about this winning thing.

He had made this lovely little charge on that Sunday, with birdies on Nos. 16 and 17, and just missed a birdie on 18. That was good enough to position him to win the Cup under the old points system. But, for the want of that last putt, Xander Schauffele edged him for the then-separate Tour Championship title.

And Thomas wants it all.

“I remember that going into this week in ’17, there were only a couple people who had won six times in a year, and I wanted to be one of those people,” said Thomas, who had five tournament victories that season, including the PGA Championship. “And I was (angry), to be perfectly honest, that I didn't win.

“I think a lot of people were shocked and a little upset about how I handled just winning the FedExCup and $10 million. But, I was like, man, I lost a golf tournament by one and I didn’t birdie 18, a par-5. I felt like I should have won the tournament. But, obviously, in the grand scheme of things, it was still an unbelievable year and my best to date. But, no, my competitive nature is never just going to be OK with losing by one even if I get a consolation; a really, really good consolation at that.”

So, let’s fast forward to next Sunday and the finish of another Tour Championship. This time there is only one prize to win. This time, under the new staggered scoring system, Thomas is starting this week atop the leaderboard at 10 under, giving him anywhere between a two- and a 10-stroke running head start on the other 29 in the field.

What happens now if he claims another FedEx Cup title — and $15 million this time — but doesn’t finish with the low 72-hole stroke total? A real possibility. Might that, um, irk him, too?

“You probably won't believe me, but, yeah, it will irk me,” he said. “World ranking points are on the line (based on raw stroke total here). And I want to beat everybody every week I play.”

The guy at the top of the leaderboard when live fire starts at East Lake on Thursday, the one with 10 under beside his name before the first real swing, seems perfectly suited for such a position.

There is nothing about being out front that should trouble Thomas. No expectation should be too heavy. No spotlight should be too hot.

No doubting Thomas when it comes to his competitive instincts. Just listen: “I want to be better than everybody else that walks the planet. It’s a pretty good feeling. I had for all of two weeks.” That was in 2018, when he briefly ascended to No. 1 in the world rankings.

Exactly the kind of win-it-all attitude you might expect from a big Alabama football fan, a school also known to produce a fair golfer or two.

Yes, Thomas even invoked Nick Saban once Wednesday when talking about how long he allowed himself to enjoy last week’s victory at the BMW Championship, in which he shot a blistering 25 under and which boosted him to the top of the FedEx Cup points list just in time for this East Lake finale. “It really is kind of the coach Saban method of the 24-hour rule – you enjoy it for 24 hours, and then it's over with.”

The BMW was Thomas’ only victory of the year, and his first since August of last year. For a 26-year-old who is always mentioned as among the leaders of the next generation of players, that represented a legit slump. You can bet he was irked.

“I think it’s pretty obvious that this year hasn't been what I’ve wanted. But, obviously, (winning the FedEx Cup) would be a great ending to a good year,” he said.

Following the Masters, Thomas missed six weeks with a wrist injury. His putting went sideways. In fact, it wasn’t until the BMW that he posted his first top-10 finish since returning from the injury.

The guy who has shot 59 on Tour, the one who has a round of 63 in the U.S. Open returned at Medinah last week. A Saturday 61 gave him ample cushion for what was a three-stroke victory. He is capable of going really low, a possibility that could wreck the Tour Championship field given the lead he already has.

The injury, it turns out, most affected his putting, which was, oddly enough, the one thing he could practice while he was hurt.

Here’s how weird the psychology of that little stroke can be: “I putted so much that I was trying to be perfect. And striving to find that perfection, I got worse, which is, quite frankly, mind-blowing and a bit concerning,” Thomas said.

“I came out of that injury thinking I was going to putt better than I ever have, and I putted worse than I have in a couple of years.”

He seemingly has righted that wrong. And should Thomas find himself at the end of the week with one putt for $15 million, he might just be able to handle the moment.

Here’s a guy who could get more all shook up over a little money game with some buddies back home. “Where this putt is $200 for the last hole, and I have to physically give my friend $200 — that makes me nervous,” he said.

Here’s a guy who comes from uncompromising stock, and we’re not talking about his dad, the club pro. In 2014 when Thomas was just getting started on the PGA Tour, he had a good week at the Memorial punctuated by a bad closing hole. His mother texted him with the message that the double bogey on 18 had cost him $42,000.

“I was like, mom, if you ever send me a text like this again, I will delete your number,” he recalled Wednesday.

Here’s a different breed of competitive cat, for sure.