SAN FRANCISCO • A few weeks ago, Brooks Koepka's chances of winning a record third consecutive PGA Championship looked to be fading after a string of poor results and a recurrence of his niggling left knee injury.

But the big man from Jupiter, Florida tends to lift off when the Majors come into orbit, and his tied second place in Memphis at the WGC-St Jude Invitational last Sunday was a typical, timely return to form.

"I feel like my game's right there. This is where we wanted to be, peaking for the PGA (Championship)," he said, having registered one top-25 finish in 10 prior starts.

"I feel like my game's right there, everything's solid."

No player has won the PGA Championship, the first Major of a disrupted year, three successive times since it became a stroke play event in 1958. The late Walter Hagen is the only player to have ever achieved the "three-peat", but Koepka's record of shining on the biggest stage - four of his seven PGA Tour career wins have been Majors - cannot be discounted.

The bookmakers have made him joint favourite alongside new world No. 1 and fellow American Justin Thomas ahead of tomorrow's tournament.

Thomas, who usurped Spain's Jon Rahm after beating Koepka to the WGC-St Jude title, will be chasing a second PGA Championship to go with his 2017 crown this week at TPC Harding Park.

His veteran stand-in caddie also has the chance of an unexpected second title of his own. Jim Mackay caddied for Phil Mickelson for 25 years, and was on the bag when "Lefty" won the 2005 PGA Championship at Baltusrol, New Jersey.

"Bones" parted ways amicably with the five-time Major winner in 2017 and picked up Thomas' bag for a tournament in Hawaii 2018 when his regular caddie Jimmy Johnson was injured. He again answered the call last week when Johnson fell sick and the pair gelled instantly, with Thomas sweeping to victory in Memphis. A second PGA Championship for both would cap a fairy-tale fortnight.

"I honestly was 50-50 on thinking if it would work out with this short notice," said the 13-time Tour winner. "I was very lucky."

Fifteen-time Major champion Tiger Woods, who will be playing only his second Tour event since February's Genesis Invitational, will be another to watch alongside Jordan Spieth. Spieth's drought dates back to his 2017 Open Championship triumph, but the former world No. 1 can this week become just the sixth player in history to secure the career Grand Slam by winning all four Majors.

Like Koepka, the American tends to save his best for when it really counts and he has been in relatively consistent form, with just one missed cut since the Tour's restart in June.

Tomorrow's field will be missing the likes of Englishman Lee Westwood, Ireland's Padraig Harrington and Italian Francesco Molinari, all of whom have decided not to play, while South African Branden Grace had to pull out due to a positive Covid-19 test last weekend.

Two-time Major champion John Daly will also be absent due to fears over the virus. The American, who has battled weight and drug and alcohol dependency issues, tweeted: "California now #1 in cases/deaths, I had knee surgery, I'm a diabetic and I don't feel comfortable flying."

AGENCE FRANCE-PRESSE, REUTERS