Rory McIlroy heads into this week's BMW Championship in Illinois needing a top-four finish to retain any hopes of repeating his 2016 FedEx Cup triumph.
McIlroy is 51st in the play-offs standings and only the top 30 on Sunday evening will go forward to next week's Tour Championship finale in Atlanta.
His winless 2017 has seen him drop to sixth in the world rankings.
McIlroy, 28, landed last year's Tour Championship which clinched him a £7.8m bonus as he won the FedEx Cup series.
The four-time major winner plans to contest next month's pro-am format Dunhill Links Championship in Scotland with his father Gerry before calling time on a frustrating campaign.
This week's event at Conway Mills will be his final tournament in the US this year if he doesn't qualify for the Tour Championship.
McIlroy has played only 15 events in an injury-plagued season and plans to take several months off to fully recover from a lingering rib injury after competing in Scotland.
The Northern Irishman will tee off alongside Scotland's Martin Laird and American Ollie Schniederjans in his first round at 17:11 BST on Thursday.