Miami - Jason Day has been careful in plotting his return from the back injury that forced him out the BMW Championship this month, but that doesn't mean he's lowering his sights at this week's PGA Tour Championship.
The world No 1 from Australia is one of five players who go into the tournament at East Lake in Atlanta, Georgia, with a chance to claim the FedExCup playoff bonus.
Although he could finish as low as tied for third and still have a chance of capturing the prize, he said he's treating the week as a must-win.
"It's either winning or nothing else matters," Day said. "That's the mentality that I have to go into because, if I finish second, that's great and all, but it may not win me the trophy.
"So I've got to go in with the mentality that I have to win."
Day thinks a victory could also give him a shot at Player of the Year honors, an award voted on by Tour members which many believed that US Open champion Dustin Johnson wrapped up with his victory at the BMW Championship at Crooked Stick.
Both players have won three times this season, with Johnson's trio of titles including his breakthrough major triumph at Oakmont.
"If I win four times, win the FedEx Cup... I'm hoping that pushes me over the line if I win," Day said.
"If we both finish tied fifth (at the Tour Championship), he obviously deserves it. My biggest thing is I've got to win, and if I win, that hopefully pushes me over the edge."
Johnson tops the FedExCup standings, and the race for the $10 million bonus that goes with the title.
He has won three of his last nine tournaments and has finished in the top 10 in his last three Tour Championship starts - tying for 10th in 2012, finishing fifth the following year and closing with a 64 last year to tie for fifth, five shots behind winner Jordan Spieth.
American Patrick Reed is second in the standings and is one of the five players guaranteed to take home the Cup with a victory this week.
He won the first playoff event, the Barclays, tied for fifth in the Deutsche Bank Championship and tied for 13th at Crooked Stick.
Johnson and Reed are paired together on Thursday, while Day will play alongside compatriot Adam Scott, who has finished in the top 10 in all three playoff events and comes in ranked third in the playoff standings ahead of Day and England's Paul Casey.
While the elite 30-man field will offer plenty of formidable competition, Day said his back won't be a factor.
"The back isn't an issue right now," said the Aussie, who said he's back in his routine for dealing with the annular tear of a disc in his spine, which requires keeping up with specialized exercises.
"I wasn't able to go the gym as much, missed a few massage sessions with my guy," Day said of the trouble that struck in Indiana. "Muscles turn off, and then my back goes out. But I learned from it. I'm going to try and get better."