Los Angeles - Six-times PGA Tour winner Hunter Mahan used to share the same swing coach as Tiger Woods and, purely as a golf fan, he has been left stunned and confused by his fellow American's recent struggle for form.
Former world number one Woods plunged new depths when he posted the worst 72-hole total of his PGA Tour career at last week's Memorial Tournament, which included a mind-boggling 13-over-par 85 in the third round.
Mahan, who got to know Woods well as a team mate for the United States at the 2010 Ryder Cup and also at the past four Presidents Cups, says the biggest thing he has noticed in the 14-times major champion is a diminished enjoyment for the game.
"I haven't watched a ton of what Tiger is doing but I have definitely watched a little bit of it because it is so confusing that a player of his calibre is struggling this much," Mahan told Reuters in a telephone interview.
"From a fan's perspective, I just don't see him enjoying the game as much as he used to. I don't know why. Technically, it's definitely not there for him after six, seven or eight months of (Chris) Como."
Woods has had four swing coaches during his professional career and began working with Como late last year after parting ways with Mahan's instructor, Sean Foley, in August.
Previously, Woods had worked with Butch Harmon and Hank Haney before joining forces with Canadian Foley in August 2010.
"You would kind of think that technically he would have a better understanding of his game or he could see what he is trying to do but it's hard to tell that," Mahan said of Woods' results with Como.
"I just don't see the enjoyment in him right now. It's sad to see because golf is the ultimate enjoyment for that guy. He loves to get out there on the golf course, he loves to compete, he loves to grind at it.
"It seems to be more of a chore to him now than it used to be and I don't want to see that because golf is better with Tiger Woods at his best. I love seeing him compete at the highest level."
Woods, who finished last among those who made the cut at the Memorial Tournament with a 14-over total of 302, has been struggling with his game for most of this season.
He has recorded just one top-25 in five starts on the PGA Tour, a tie for 17th at the Masters in April, while his world ranking has shockingly plummeted to 181st.
Asked if Woods had worked too many coaches, Mahan replied: "To me, this doesn't seem technical.
"There are probably certain aspects of it that he is definitely not where he needs to be but to see what he is doing when he plays courses where he has had an enormous amount of success at, it seems beyond technique.
"There is something else going on. I think there are a lot of underlying things we don't see. I don't see him coming out to the golf course and being excited any more. Golf should be enjoyed, he should have great pleasure in it."
Mahan, whose six PGA Tour wins include two at the elite World Golf Championships where the game's top players compete, was speaking to Reuters after his new partnership with credit card Chase Sapphire Preferred was launched earlier this week.
Through this partnership, a contest will be run on Twitter and Instagram with the winner going on to enjoy an 'inside the ropes' golf experience with Mahan before the year's final major, the Aug. 13-16 PGA Championship at Whistling Straits.
"They will allow this fan to come out on the course with me for a little bit, to kind of experience what it feels like to be a pro golfer at a big event," Mahan said of the opportunity, which will take place on the last day of official practice.
"I will be able to talk to the fan about what I am thinking about on that golf course and how I want to play the next shot -- kind of one-on-one golfing tips."