ATLANTA – Justin Thomas has 15 million reasons to keep his thoughts to himself.

Thomas was the first player to take a lead into the first round of the Tour Championship with the introduction of last year’s staggered scoring system. But after starting the week at 10 under par, he struggled the rest of the way and finished tied for third, five strokes behind FedExCup champion Rory McIlroy.

So what advice would he give this year's pre-tournament leader, Dustin Johnson?

“Without being disrespectful, I really don't feel like saying that, because I don't want to give [him] any advice or things that I wish I would have done better,” he answered.

Thomas admitted that it was a strange feeling starting the week with a lead, and he never felt comfortable with the new format.

“It was tough. It was different,” Thomas said. “That's the best way to describe it. There's nothing that we could simulate or that we've done that when you put your tee in the ground on the first round, you start at 10 under and everyone is behind you.”

Thomas will start this year’s finale third on the points list and at 7 under. Jon Rahm is second and is at 8 under followed by Webb Simpson (6 under) and Collin Morikawa (5 under) rounding out the top 5.