Australia's 2013 Masters champion Adam Scott and 2019 Open Champion Shane Lowry of Ireland are also teeing it up at Sedgefield Country Club in Greensboro, North Carolina, vying to qualify for the US PGA Tour's FedEx Cup playoffs in the final regular-season event.
Thomas, who won the PGA Championship in 2017 and 2022, has missed six cuts this year, including five in his past seven tournaments.
He missed the cut at three major championships this season and is ranked 79th in the playoff standings, with only the top 70 at the end of this week advancing to the tour's season-ending series.
"I'm obviously not playing as well as I have in the past, but I'm not playing that poorly," Thomas said this week. "I haven't really gotten much out of my rounds."
Thomas, who is also running out of time to make a case for a Ryder Cup berth, added last week's 3M Open in Minnesota to his schedule in a bid to gain playoff ranking points, but he missed the cut after a second round that included two double bogeys.
"That is golf," Thomas said. "What is happening this year, it happens every single year. Someone of, I don’t - I mean, my caliber, you know, a top player - I'm not having a bad season; I just haven't won anything, haven't finished tournaments off how I want."
Scott, who has played in every PGA Tour playoffs since they were instituted in 2007, said much the same on Wednesday.
"One better round of golf this year and I'd find myself well inside the FedEx Cup line at the moment," said Scott, who is 81st in the standings.
The Aussie has played 16 tournaments this year, making the cut in 14 with three top-10 finishes. He said the pressure this week's do-or-die scenario could be beneficial.
"It's like qualifying for a tournament except this is kind of a four-day qualifier for me," he said. "Sometimes that can really help you, it can intensify your focus and get the job done."
Good, not great
Lowry, who has just one top-10 finish in 17 starts this season, is playing for the first time since a "pretty bad week" at the Open Championship, where he missed the cut.
Otherwise, Lowry said, "I think there's been a lot of good, not much great, which on the PGA Tour doesn't cut it.
"You need those great weeks, you need those top-fives to move up the FedExCup points list."
Nevertheless Lowry, 76th in the standings and chasing his first win since his Open triumph at Royal Portrush, believes he can extend his season.
"I think it's easy to sit here and go, 'Oh, I just want to play well, I want to go out and try and win the tournament. No, at the end of the day, I want to make it into next week, I want to make it into the playoffs and I want to make a run at the playoffs," he said.
