Adam Scott continues to be the best-placed Australian after the third round of the Deutsche Bank Championship.
But world No.6 barely made an impression on the leaders after carding a one-under par 70 to trail England's Paul Casey by 10 strokes in the US PGA Tour's latest FedEx Cup playoff event.
Scott is in a tie for 23rd while compatriot and world No.1 Jason Day is a shot further behind after returning his best round of the tournament with a three-under par 68 at TPC Boston.
Day's round included five birdies and an eagle, but a double bogey on the 10th hole stalled any chance he had of getting into a position to challenge on the final day.
Nevertheless, Day worked out the kinks after two mediocre opening rounds, spending ample time at the driving range.
He struggled with his driver leading up to Sunday's round, but had only one bad shot off the tee at the 10th hole - resulting in his double bogey.
Day capped his round with an eagle at No.18, placing his approach shot seven feet off the cup before dropping the putt.
He is tied for 33rd place with reigning Deutsche Bank champion and world No.8 Rickie Fowler, who posted a 69, and US Open champion and world No.2 Dustin Johnson.
Aaron Baddeley is at one-under par after shooting 71 while Marc Leishman slipped out of contention with a three-over par 74.
Casey also had an eagle at the final hole to jump into a three-stroke lead.
The Englishman's approach shot from 235 yards at the par-five 18th landed just in front of the green and rolled up to inside a foot of the hole.
He tapped in for a third consecutive five-under 66.
Casey posted a 15-under 198 total, with American Brian Harmon (68) in second place on 12-under.
The 39-year-old has won 13 times on the European Tour, but only once in the United States, where he now plays almost full-time.
"To be sitting here at 66, I'm obviously over the moon," Casey said.
"Even with the great ball-striking, I found it difficult at the beginning, but to turn it around and have a lot of looks for birdies and make a few to come in, it's been great."
