As speculation continues to swirl about whether he'll jump to the rebel LIV Golf circuit, Australian world No.2 Smith birdied two of the last three holes to shoot a three-under 67 at the FedEx St Jude Championship in Memphis on Saturday.

Already the winner of the Tournament of Champions, Players Championship and British Open this year, 28-year-old Smith trails only American leader J.J. Spaun (68) and second-placed Austrian Sepp Straka (68).

He is in a three-way tie for third with Americans Will Zalatoris (65) and Trey Mullinax (66).

He is keenly aware that a victory would take him to the world No.1 ranking for the first time after current No.1 Scottie Scheffler missed the cut on Friday. He would join Greg Norman, Adam Scott and Jason Day as the only Australians to achieve that feat.

"That would mean a lot," said Smith.

"That's been one of my goals probably since the start of the year is to try to get to that top spot and chase it down."

Of the other Australians, Adam Scott fell to tied 25th, six shots from the lead, after a round of 70, whileCam Davis (67) is tied 36th at five under and Marc Leishman is last at three over after a 75 containing six bogeys and a double bogey.

Spaun had a two-putt birdie on the par-5 16th and holed an 18-foot birdie putt on the next hole to claim the 54-hole lead a 13-under 197.

Straka was right there with him until he failed to save par from the bunker on the 18th.

Both are first-time winners on the PGA Tour this year, and a victory in a FedEx Cup playoffs even carries even more weight - $A3.78 million to the winner and a guaranteed spot at East Lake for the FedEx Cup finale.

But there are a host of players in contention, with 16 within four shots of the lead, including stars Sam Burns and Tony Finau.

But no one stands out like Smith, for so many reasons.

Not only is it his first start since being introduced at St. Andrews as the "champion golfer of the year," the UK's Daily Telegraph reported on Tuesday that he had signed with LIV and would join the defectors outside Boston after the PGA Tour playoffs are over.

Smith has steadfastly refused to talk about it, only to say he's only thinking of the FedEx Cup.

"I'm a man of my word and whenever you guys need to know anything, it'll be said by me," Smith said Tuesday. That was shortly before a California federal judge denied a request by three LIV golfers to play in the FedEx Cup playoffs.

Distractions don't seem to be an issue, and there is no shortage of them.

"There's definitely been a few more, but for me, I'm just trying to hit the best shot I can," Smith said. That's what I'm here to do is to hit good golf shots and make birdies."

Davis, Scott and Leishman also have a lot to play for in the final round.

All enter Sunday with the threat of suffering the top-70 cut-off to advance to next week, currently projected to finish 64th (Scott), 67th (Davis) and 69th (Leishman).

with The AP

Australian Associated Press