Justin Thomas, Jordan Spieth pushing each other again at The Tour Championship

ATLANTA — They’ve known each other for a decade now, Jordan Spieth and Justin Thomas have, since the days they battled on golf courses as kids.

The two went mano a mano as teens, too, and then faced off against one another in the college ranks, where Spieth was part of a national championship squad at Texas and Thomas was part of a national champion at Alabama.

And their relationship on and off the golf course has continued into the pro ranks, on the game’s biggest stages on the PGA Tour, the best professional circuit on the planet. It’s no surprise, then, that the 24-year-olds — Thomas is three months older than Spieth — have driven each other for years.

Well, they’re pushing each other again this week at the season-ending Tour Championship and FedExCup Playoffs finale at sunbaked East Lake Golf Club. As a byproduct of their outstanding play this season — they’ve won eight titles and two majors between them — the two were paired for an astounding 15th time this year in Friday’s second round of The Tour Championship.

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No, they are not sick of each other. And no, they are not completing each other’s sentences. For the two, who have played hundreds of friendly practice rounds together, it’s just business as usual.

“We're both doing our own thing out there, we're not out there to entertain each other,” Thomas said. “It's just a nice bonus sometimes between shots but that's about it.”

Added Spieth: “We enjoy it very much. It's fun to play together. We've done it for a number of years.”

But this has been a special year. Spieth was in the same group when Thomas shot 59 in Hawaii en route to victory. They have played the first two rounds of each of the four playoff events together, including the Dell Technologies Championship where Thomas won and Spieth finished runner-up.

They were there for each other off the course, too. Just beyond the 18th green at Royal Birkdale, Thomas was there to congratulate Spieth after he won his third major championship at the British Open. Spieth returned in kind just to the side of the 18th green at Quail Hollow when Thomas won his first major at the PGA Championship.

Not counting the two rounds they played together at the Zurich Classic, which was a team event, little has separated them in their head-to-head contests. Spieth has taken 884 shots and averaged 68.00 per round; Thomas has taken 875 shots and averaged 67.31 per round.

They won’t be paired for Saturday’s third round, however, but remain in contention for the FedExCup, the Tour Championship and the $10 million bonus. Thomas got the best of Spieth with a 4-under-par 66 in the second round, which he capped with an eagle 3 on the last hole. Spieth struggled throughout and managed a 70.

Thomas is at 7 under through 36 holes and tied for the lead with Paul Casey and Webb Simpson. Spieth is a 3 under and in a tie for 15th.

Thomas has leapfrogged Spieth in the race to the FedExCup and the $10 million. He is projected to win the Cup after two rounds, with Casey No. 2, Simpson No. 3 and Spieth No. 4. Spieth won the lucrative double — The Tour Championship and the FedExCup — in 2015.

As well, Thomas will be chasing his sixth win this season while Spieth will be going for his fourth. Barring injury, a couple more decades of Spieth vs. Thomas is in the offing, two of the game’s best giving each other their best for years to come.

But it hasn’t always been that way.

When Spieth quickly broke out of the professional gates, winning two majors and six Tour titles before Thomas won his first tournament, the narrative was not kind to Thomas. He was basically referred to as Spieth’s good friend and was a magnet for scribes wanting material about Spieth.

Thomas always delivered, speaking with admiration about Spieth, but reading between the lines, you sensed the fire was building inside. He has said he was jealous of Spieth’s success and, while Thomas is himself his biggest motivator, the pursuit of Spieth didn’t hurt.

“I mean, I was extremely happy for him, but I was jealous,” Thomas said after he won the Wanamaker Trophy at the PGA. “I'm not going to lie or sugarcoat anything, I was very jealous. I wanted to win a major.”

Thomas has also closed the gap — he has six PGA Tour victories to Spieth’s 11. But as much as Thomas wants to catch Spieth, he just wants to win.

“We always want more and I want to win because I like winning, not because Jordan’s won more than I have,” Thomas said. “It's nice to be a little bit closer in the total wins column but I like winning because I like having my name on trophies, I like being known as the defending champion, I like adding things to my resume and setting records.

“I was jealous of Jordan. I'm still jealous that he's won three majors and I've only won one, but I don't go out there practicing like he's won three, I've won one. It's like I want to go win two, I want to win that second one sort of thing.”

Let their games continue.