Rory McIlroy expressed his frustration at not getting back into contention for a second US Open title as Jason Day tried to remain there at Chambers Bay on Saturday.
McIlroy carded a third round of 70 to remain four over par just after Day teed off at two under, three shots behind halfway leaders and Ryder Cup partners Jordan Spieth and Patrick Reed.
Day was walking from the elevated tee on the par-three ninth - his final hole - during the second round on Friday when he suddenly collapsed, the 27-year-old later being diagnosed as suffering from Benign Positional Vertigo.
The world number 10 received treatment at a local medical centre and opted to continue in the tournament, opening his round with a perfect drive down the fairway and narrowly missing for birdie before picking the ball very gingerly out of the hole after tapping in for par.
McIlroy had marked his par on the 18th with a mock celebration after finally holing a lengthy putt, the world number one missing numerous birdie chances after picking up shots on the second and seventh.
"I missed seven good chances on the back nine, or seven makeable putts, anyway," said McIlroy, who dropped shots on the 11th and 15th. "It was just nice to see one drop at the last there. I feel like I turned a 65 into a 70 today.
"Whenever you start to miss a couple you start to get a little tentative. You start to doubt yourself. You start to doubt the greens a little bit. And then it just sort of snowballs from there. I holed a few nice ones early on, but once I missed a couple it got into my head and couldn't really get out of it."
Henrik Stenson had memorably likened the greens to putting on broccoli, but McIlroy joked: "I don't think they're as green as broccoli. I think they're more like cauliflower.
"They are what they are, everyone has to putt on them. It's all mental. Some guys embrace it more than others, and that's really the way it is. It is disappointing that they're not in a bit better shape. But the newer greens like seven and 13, they're perfect.
"I played last Sunday and I felt like they (the USGA) brought it a little too much towards the brink then. And it's always a struggle from then to sort of rein it back little bit. I would have liked to see them keep it a little greener for the practice rounds and then gradually as the tournament progresses get a little firmer.
"That might have kept the greens in a bit better shape, but you never know. I've never been here before, but I hear that the weather isn't always like this. If there had been a little bit of moisture and had it been overcast the greens might not have gotten baked out and as bumpy as they are."
McIlroy admitted he was frustrated to four-putt the 17th and drop another shot on the 18th in his second round, but was happy to have ground out a score after missing the cut in his previous two events.
"I'm pleased with how I've kept it going," the 26-year-old said. "It's a lot easier to do that than when you're not hitting fairways and not hitting greens. I'm hitting great shots and great drives and giving myself chances the whole time.
"It's just hard to stay patient whenever I'm not holing anything. I feel mentally I've accepted most things this week, which is good."
It has taken a remarkably insightful 21-year-old to put a professional perspective on the quirky challenge of Chambers Bay. "If you are going to talk negative about a place," said Jordan Spieth, "you're almost throwing yourself out to begin with because golf is a mental game."