May 14 (Reuters) - LIV Golf's Brooks Koepka will launch his PGA Championship title defence on Thursday alongside Jordan Spieth and Max Homa while tournament favourite Scottie Scheffler is grouped with fellow major winners Wyndham Clark and Brian Harman.

Koepka, bidding to become the tournament's first repeat winner since he retained the title in 2019, will go out in the eighth group from the 10th tee at 8:37 a.m. ET (1237 GMT) followed by a 2:02 p.m. ET start on Friday from the first tee.

The five-times major winner arrives at Valhalla Golf Club in Louisville, Kentucky, fresh off a LIV Golf event in Singapore where he won his fourth title on the Saudi-backed circuit.

Playing two groups ahead will be a trio consisting of world number two Rory McIlroy, who on Sunday earned his 26th win on the PGA Tour, Justin Rose and LIV Golf's Dustin Johnson.

Tiger Woods, who has not played a PGA Championship since 2022 when he withdrew in pain after the third round, will be a further group ahead, teeing off at 8:04 a.m ET alongside Keegan Bradley and Australian Adam Scott.

For Woods, this will mark his first event since the Masters where the injury-ravaged golfer earned a tournament-record 24th consecutive made cut at Augusta National and then finished last among those who played the weekend.

World number one and new dad Scheffler will be bidding for a fifth win over his last six starts when heads out from the first hole at 2:13 p.m. ET on Thursday in the company of reigning U.S. Open champion Clark and British Open champion Harman.

Reigning Masters champion Scheffler, whose son Bennett was born last Wednesday, will have had 24 days off since his last round of competitive golf by the time he tees off on Thursday at the 7,609-yard Valhalla layout.

The first shot of the tournament will be struck at 7:15 a.m. ET by Michael Block, the club professional who produced a feel-good story at last year's PGA Championship where he recorded a top-15 finish and was a fan favourite throughout the week.

According to the forecast, cloudy skies and a 20% chance of rain are expected on Thursday before a low-pressure system brings showers and thunderstorms to the region on Friday with the potential for more heavy rainfall at times.