Defending Champion Jason Dufner, is under no illusions about the task that lies ahead this week at Valhalla, if he is to repeat his stunning PGA victory achieved at Oak Hill last year, when he held off Jim Furyk to claim his first Major Championship.
The 96th PGA Championship, the final Major of the year, tees off on Thursday at Valhalla in Kentucky, the scene of America's only Ryder Cup victory this century, when Nick Faldo's European's surrendered in the face of a highly charged and partisan crowed by, 16½-11½.
It is also the scene that Tiger Woods, joined Walter Hagen and Gene Sarazen, as the only men to win back-to-back PGA Championships, when he defeated Bob May in a three-hole playoff to lift his fifth Major title, way back in 2000.
The fact that only three-players since 1916, have managed to defend their titles in the fourth Major of the year, underlines the task that lies ahead for the 37-year old Dufner, and one that he acknowledged with his fans on Facebook will be a stern test.
"Returning as defending champion will be a great test of my game because there have been very few back-to-back winners."
Dufner has bitter sweet memories of the PGA Championship, after coming so close in 2011, and then finally lifting the Wanamaker Trophy last year to claim his first Major.
In 2011 at the Atlanta Athletic Club in Johns Creek Georgia, Dufner entered the final round with a share of the lead alongside Brendan Steele and promptly went through the first 14-holes bogey-free, while Steele wilted under pressure, dropping four shots.
Arriving on the 15th tee, Dufner, held a five-shot advantage over Keegan Bradley, however drop-shots on 15, 16 and 17, coupled with birdies for Bradley on 16 and 17, forced a two-way playoff, Bradley eventually winning over the three-holes, to clinch his first and only Major Championship.
Last year at Oak Hill, Dufner managed to wipe away the 2011 memories, when he held off Jim Furyk by two-shots, finishing on 10-under.
His victory was built on the foundation of a superb second round course record of 63, which included five-birdies and an eagle.
Speaking ahead of his defence at Valhalla, Dufner recalled: "Winning the PGA Championship, my first major, was a lifelong dream of mine and it’s hard to explain how great it felt."
"It’s sad knowing my year as champion is almost ending, but I think trying to win it again will be a great test," he added.
Six years on from the Ryder Cup experience, that will no doubt still haunt the European charge this week when you consider some of the form players like Justin Rose, Sergio Garcia and Henrik Stenson to name a few, were all in action on that fateful weekend back in 2008, however they will be arriving this week to a course that has been completely revamped.
A multi-million-dollar facelift has been given to the course over the last year, under the watchful eye of the great Jack Nicklaus.
The refurbishment has seen all 18-greens be rebuilt, all bunkers have been upgraded, a new irrigation system has been installed which means firmer fairways, and for those that aren't straight off the tee the rough is far longer, suggesting that the challenge doesn't only apply to Dufner, but to the entire field.
Rory McIlroy arrives as hot favourite after clinching his third Major at the Open Championship last month at Hoylake and then went on to underline that status on Sunday, with victory in the WGC-Bridgestone Invitational.
The Northern Irishman, back on top of the world rankings, has held off Sergio Garcia on both occasions, the Spaniard expected to challenge this week at Valhalla once again.
Justin Rose, the 2013 US Open Champion, and a winner on both the European and PGA Tours this season, finished tied fourth on 9-under-par last week and will again be expected to feature in the last of the groups come the final day.
2011 PGA Champion Keegan Bradley, who alongside Dufner, Rickie Fowler, Patrick Reed and Ryan Moore should lead the US charge, while world number two Adam Scott and Charl Schwartzel, both Major winners and both with strong performances last week at Firestone, could also feature coming into the final day.
Jason Dufner wins the 2013 PGA Championship
Phil Mickelson, the 2005 PGA Champion, last won a Tour event at the 2013 Open Championship, however a closing 8-under 62 on Sunday, suggests that the 44-year old could be bringing his best form into Valhalla, and could add a sixth Major to his collection come Sunday.
Doubt still remains over whether Tiger Woods will be in a position to win a fifth PGA, after withdrawing during the final round at Firestone on Sunday, citing back spasms. Woods has only recently returned from back surgery which has kept him out of the game for the best part of three-months, and a decision on his fitness could be made the night before the event.
If fit, Woods will play on Thursday and Friday alongside Padraig Harrington and Phil Mickelson, while Bubba Watson, Rory McIlroy and Martin Kaymer are together for the first two days and with 29 Majors between them expect much of the attention to be around these two groups.
Dufner gets the defence of his Championship underway alongside the man that defeated him in the 2011 playoff, Keegan Bradley, and Korea's Yang Yong- Eun, while Adam Scott, Jordan Spieth and Lee Westwood is another group that is sure to draw in the galleries.