Adam Scott not using Steve Williams as caddie for PGA

In a bid to shake up his lackluster season, Adam Scott will rest caddie Steve Williams from a major championship for the first time in more than two years.

Scott, ranked No. 17 in the world, confirmed he will use his part-time bagman David Clark at next week's PGA Championship and this week's World Golf Championships-Bridgestone Invitational in Ohio.

Williams was on the bag for 13 of Tiger Woods' 14 major titles before helping Scott to his breakthrough 2013 Masters victory and his ascension to world No.1 in 2014. Williams hasn't missed a major with the Australian since the 2015 Masters.

That absence from Augusta was due to Williams' retirement before Gold Coast native Scott lured him back part-time for only the biggest tournaments on his schedule.

The PGA Championship, starting Aug. 7 at Quail Hollow, will be just the second time 53-year-old Williams hasn't carried Scott's clubs at one of the four big dances since the 2011 U.S. Open.

"Clarkey is caddying next week. He hasn't caddied for me for 15 weeks so he needed to come out here," Scott told AAP.

"He's only caddied five times for me this year. It's very difficult; you have to balance two caddies."

The 37-year-old Scott is winless since February 2016 and currently sits 70th on the PGA Tour's season-long FedEx Cup race.

Given Scott plans to skip the first two FedEx playoff events to be with wife Marie as she gives birth to the couple's second child, due Aug. 19, he risks falling out of the top-70, which progress to the third playoffs tournament - the BMW Championship.

"I'll have to play exceptionally well the next two weeks to make it to the BMW," said Scott, who won the WGC-Bridgestone in 2011.

"These are two big weeks; a WGC event and a major. It would go a long way toward feeling good about the year.

"There has been a lot of average golf. It's frustrating because I haven't been able to put it all together."