And the payoff could be enormous.
Sloppy at the turn, Casey kept a clean card on the back nine at East Lake and holed a 40-foot birdie putt on the 17th hole for some separation in the Tour Championship. He shot a five-under-par 65 to build a two-shot lead, leaving him one round away from his first PGA Tour victory in eight years and 144 events.
His last victory was the Houston Open in 2009, though he has won five times around the world since then.
Different about this opportunity is the $10-million bonus if he were to win the FedEx Cup, and the 40-year-old from England headed home Saturday evening knowing he was projected to capture both trophies.
“It would be amazing,” he said.
Casey, who was at 12-under 198, has six top-5 finishes in his last eight FedEx Cup playoff events.
Kevin Kisner had a 64, his best round at East Lake by three shots, and still rued too many birdie chances that burned the edge of the cup. He left East Lake in a hurry without too much reflection on his round or his chances so he could take a helicopter to Georgia's football game.
Also two shots behind was Xander Schauffele, the PGA Tour rookie who looks comfortable on a big stage against some players he hasn't had the occasion to meet this year. The 24-year-old from San Diego made it into the Tour Championship by playing his final six holes in 6-under par last week at the BMW Championship. He showed that explosive scoring again in the third round at East Lake for a 65.
“I had nothing to lose last week, and I have absolutely nothing to lose this week,” he said.
The top five seeds in the FedEx Cup only have to win to claim's golf's biggest payoff, and those numbers are dwindling.
Justin Thomas, the No. 2 seed and a five-time winner this year, was tied for the lead and played in the final group with Casey. He fell back with a three-shot swing on the par-5 sixth hole when Casey made eagle and Thomas missed the fairway and chopped his way to a bogey. Thomas made a double bogey on No. 14 from another wild tee shot and a three-putt from about 35 feet.
Two birdies over the last three holes gave him a 70, and he was still in the mix at five shots behind.
Jordan Spieth, dressed all in black, opened the back nine with consecutive bogeys, and then missed a 3-foot birdie putt on No. 12.
He put together three birdies to salvage a 69, though he was eight shots behind. Even so, as the No. 1 seed, the FedEx Cup was not out of reach. Spieth could still move up the leaderboard, though he likely would need someone other than Casey to win, and to stay near Thomas on the leaderboard.
“Unfortunately, I'm not really in control of my own destiny at this point, but I'll go out tomorrow, try and shoot a really solid round of golf and then do some cheerleading,” Spieth said.
Jon Rahm, the No. 5 seed, had to settle for a 70 and was six shots behind. Dustin Johnson (No. 3) had a 69 and will be paired again Sunday with Spieth in a tie for 13th.
Casey is not tempted to think about a $10-million bonus — $9 million paid out immediately — or even the five-year exemption that comes with it.
Having gone so long since that last PGA Tour victory in Houston, and knowing Spieth or Thomas could finish behind him and still win the FedEx Cup, he wants to leave town with at least one trophy.
“For me, the most important thing is to try to win the Tour Championship,” he said. “I was told some of the scenarios, and I said, `It's all irrelevant if I don't get the job done.“’