Bryson DeChambeau needs to improve his mental rather than physical strength to contend in major championships, according to three-time European Tour winner Nick Dougherty.
DeChambeau's physical transformation has been the main talking point since golf's return to action following the coronavirus shutdown, with the American putting on 20lbs of muscle to become an incredibly long hitter.
The approach has paid off with a string of six consecutive top-10 finishes followed by victory in the Rocket Mortgage Classic, but DeChambeau's on-course behaviour has left plenty to be desired.
During the third round in Detroit, DeChambeau reacted to a poor bunker shot by throwing his club into the sand and then confronted the cameraman who had captured the moment at some length, later complaining that the footage could "damage his brand".
On his next start at the Memorial Tournament, DeChambeau was again the centre of attention as he ran up a 10 on the 15th hole in round two, during which he argued with a referee over whether his ball was out of bounds, complaining: "They're giving me a garbage ruling like usual."
To date DeChambeau's best finish in 11 majors as a professional is a tie for 15th in the 2016 US Open and, speaking ahead of the US PGA Championship at Harding Park, Dougherty told the PA news agency: "Mentally he's got some changes to adapt to. I think we've seen glimpses of it recently.
"When you're on the screen all the time, which he has been recently, every single thing you do is monitored and judged so it's hard, because you do make mistakes and then we jump on it because that's our job.
"But I think mentally is where he can make up that ground in majors because the majors are typically the most enjoyable to watch but the most unfair of challenges, US Open particularly.
"You get tough breaks, around the greens it can be really brutal, and the reactions we saw from him at Memorial, that's not major championship winning mentality.
"It is one instance so I'm not judging him on it completely, but that can't afford to happen to win majors. He's brilliant at learning lessons, he's quick to pick up on things so maybe he's going to do all that and it will help him be a better major championship player.
"With his game he will definitely contend. It's when, rather than if."
Dougherty admits he was sceptical when DeChambeau set about bulking up to gain distance, but concedes the 26-year-old's recent results are tough to argue with.
"I admire Bryson, I think it's intelligent what he's doing," added Sky Sports presenter Dougherty, who finished 51st when Harding Park hosted the WGC-American Express Championship in 2005.
"I doubted it massively. When he first came to Abu Dhabi (in January) I thought it was naive. You change your body type that much it's dangerous, there's very little evidence to support anyone ever doing that and it being the right choice. It usually ends careers rather than makes them.
"He's proved us wrong so far and his results have been so consistent. As Tiger (Woods) said, the most impressive thing about it is not just that yardage, it's that he's as accurate, if not a fraction more.
"It looks like an almighty thrash but when you break it down and slow that swing down he probably moves in a better manner than he used to. He's decided 'This is how I'm going to revolutionise, this is how I'm going to move up', and he has done so far."