Day needed a top-17 finish at the Ocean Course to find his way into the top-60 in the world rankings but a one-under 71 final round was only good enough to get into a tie for 44th.

The result saw him drop from 65th to 67th in the rankings and thus miss the first cut off for a spot in June's US Open at Torrey Pines, where he has won two of his 12 PGA Tour titles.

Day must now force his way into the top-60 over the next two weeks but he won't play at the upcoming Charles Schwab Challenge, due to the impending birth of his fourth child, meaning he will have just one start, the Memorial Tournament in his adopted American home of Columbus Ohio, to make his move.

Day will need a high finish at Muirfield Village which has undergone a significant renovation over the past 11 months, wiping out a bunch of his acquired local knowledge.

But with his ill-fated putting improving significantly over the weekend rounds at Kiawah Island, Day was upbeat and said if he does miss out on Torrey Pines he knows it will be a temporary setback on the path to a long-term fix.

"I started getting a lot more trust in my putting this weekend which is good as the speed and line are starting to tighten up, so the putt is coming out where I'm intending it to," Day told AAP.

"I'm pleased with the progress and while it would've been nice to make it into Torrey this week I have to look it as part of the journey back to where I need to be. I can't force it.

"I need to trust the processes we are all going through to get my game back to where the top-50 isn't even a thought.

"I want to be back to where number one is the goal.

"Which means I can't let one US Open steal my focus.

"I want to play 15 more US Opens and the way to ensure that is to keep working hard and keep building my confidence."

Jason Scrivener finished as the leading Australian at one-over for the week, T23 in just his second major.

"I'm pretty happy all in all," Scrivener told AAP after his final round 69 on Sunday.

"I played great except for a small stretch on Friday and while I've got lots of belief in myself until you prove it on the big stage you never know if you can compete.

"I'll take heaps of confidence from this and hopefully I can build on it and get into more majors."

That quest started immediately as he hopped a flight to Denmark to play the next two European Tour events that double as US Open qualifiers.

The top-10 players on a mini money list make it to Torrey Pines.

Scrivener is also all but assured a spot in The Open Championship via his Race to Dubai points.

Australia's top-ranked player Cameron Smith slid to a 77 and seven-over finish.

Matt Jones finished strong with a 68 to get to two-over and T30, Cameron Davis (72) finished up seven-over with Lucas Herbert (72) nine-over.

- Ben Everill