Dustin Johnson has made a habit of thriving in the latter part of the US PGA Tour season, good reason for him to be excited about his title defence at this week's Barclays tournament in Farmingdale, New York.

The long-hitting American is the only player in the elite 125-strong field assembled at Bethpage State Park to have won FedExCup play-off events in each of the last two years and is eager to launch his bid for a third in Thursday's opening round.

"I play well at this time of the year usually, so I enjoy the FedExCup," Johnson said while preparing for the first of the US PGA Tour's four lucrative play-off events.

"I like the play-offs. This is time where you really need to play well. I've had a lot of success the last few years in the play-offs, and hopefully I can continue that this year."

Two years ago, Johnson won the third play-off event, the BMW Championship, before winding up fifth in the final FedExCup standings.

Twelve months ago at a rain-softened Plainfield Country Club in Edison, New Jersey, he triumphed by two shots at The Barclays, which was cut to 54 holes because of Hurricane Irene.

"It's at a totally different golf course than it was last year," said Johnson, referring to the challenging 7,468-yard Bethpage Black layout which staged the US Open in 2002 and 2009.

"It's going to play tough. The rough is pretty thick, and the fairways are pretty narrow, just like they were in the US Open. It's going to be a good test of golf.

"The FedExCup, that's what it's all about. I've got to have three good weeks if I want to make it to the Tour Championship."

The top 100 players in the points list qualify for next week's Deutsche Bank Championship in Boston, with the leading 70 there advancing to the BMW Championship. The top 30 then qualify for the Tour Championship finale in Atlanta where the overall points winner pockets a $10 million bonus.

Tiger Woods, a triple winner on the 2012 US PGA Tour, will start the play-offs from the pole position this week as overall points leader. Jason Dufner is second, US PGA Championship winner Rory McIlroy third and Zach Johnson fourth.

As is customary at the play-offs, the top-three players are paired up for the first two rounds. With Dufner having opted to skip this week, Woods, McIlroy and Johnson will tee off together on Thursday in a high-profile grouping.

"I know the crowd will be pushing them quite heavily, and it'll be fun," said 2007 Masters champion Johnson. "I'm going to relish the opportunity."

All four of this year's Major winners will be competing at Bethpage Black where Masters champion Bubba Watson has lofty ambitions.

"My expectations are always high," said the long-hitting left-hander. "I've been playing pretty solid all year with a lot of top 25s but not a lot of top 10s, not as many as I want.

"These play-offs are the most important thing right now and this course sets up pretty good for me, with it being a little bit longer."

While Woods, McIlroy and Zach Johnson hold an advantage in the FedExCup standings coming into this week, the way the play-offs have been structured can allow for dramatic surges by lesser ranked players.

Three years ago, unheralded American Heath Slocum crept into a 125-man field as the 124th-ranked player but edged Tiger Woods on the final hole for The Barclays victory and catapulted to third in the standings.

Intriguingly, Slocum occupies that identical 124th spot coming into this week.

"I'm just glad to be here at this point ... so I'm going to make the best of it," said Slocum. "I've been in this situation before. I feel like my game has kind of rounded into shape. The goal is to move on. Simple as that."

Reuters / Eurosport