(Reuters) - Marc Leishman is precariously placed heading into this week's BMW Championship, well aware that it is "pretty much win or go home" in his quest to book a spot in the PGA Tour's season-ending Tour Championship later this month.

Australian Leishman qualified in the 70th and final spot for the third of the four FedExCup playoff events, to be played at Crooked Stick in Carmel, Indiana, and needs to finish no worse than third on Sunday if he is to advance.

Only the leading 30 in the FedExCup standings after the BMW Championship will move on to the Sept. 22-25 Tour Championship finale in Atlanta.

"It's pretty much win or go home for me," Leishman, 32, told reporters at Crooked Stick on Tuesday while preparing for Thursday's opening round. "I don't know where I have to finish. Third? There you go.

"That's all you're thinking about is a good chance it will be my last tournament of the year, so try and make it a really good one. If it is a really good one, I'll get to Atlanta. If not, I can spend a month home with my kids.

"But having said that, I really want to get to Atlanta. It's been seven years since I've been there (in the top 30)."

Leishman, whose only PGA Tour victory came at the 2012 Travelers Championship, was in an upbeat mood after narrowly securing his spot at Crooked Stick by tying for 46th at the Deutsche Bank Championship on Monday.

The Australian closed with a four-under-par 67 at the TPC Boston after pocketing four birdies, along with a double-bogey, in his last nine holes to inch up from 71st to 70th in the FedExCup standings.

"The game's decent, feel like it's been pretty close all year but just the results haven't been what I would like," said Leishman, who has recorded just two top-10s in 24 starts on the 2015-16 PGA Tour.

"Hopefully have a good week this week. It's pretty simple what I have to do - top two or three - so, yeah, play to win."

(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)