There was genuine concern as Australian Jason Day collapsed to the ground while playing the ninth hole Friday, his final hole of the second round.

The World No. 3 ranked Day, at first appeared to slip, but TV replays later showed he simply went to the ground as if he had fainted.

It was first thought Day may have been hit by a golf ball but that was soon ruled out.

Chambers Bay medical personnel were quick to attend to Day but it clearly took the Queensland-born many minutes to regain his composure.

Photographers started to take pictures, but playing partner Jordan Spieth waved them off but when Day sat up, Spieth kept playing bodyguard with the photographers.

Concern for Aussie Jason Day who collapses with ‘vertigo’ at his last hole on day two of the 2015 U.S. Open

“I turned around and he was just laying there,” Spieth said.

Day withdrew from the AT&T Byron Nelson after feeling dizzy three weeks ago. He received multiple tests, but nothing was conclusive. Day addressed how he was feeling earlier this week.

Day’s tee shot at the par-3 ninth hole had gone into a greenside bunker, and Day managed to play his shot onto the green. His playing partners, Justin Rose and Spieth, let him putt first as it was clear Day was still not feeling well.

Day two-putted for a bogey to shoot even-par 70 and complete 36 holes at 138, 2 under par. He slowly made it to the side of the green afterward to seek more medical attention, and then hopped on a cart for a drive to the scorer’s trailer to sign his scorecard.

His caddie/coach, and fellow Australian Colin Swatton said that it was similar to an episode that Day had at last year’s World Golf Championship event at Firestone in Ohio. Day had completed two holes on Sunday when he had to withdraw because of dizziness that was later diagnosed as vertigo.

Day’s wife, Ellie, who is pregnant with their seco

World No. 3 Jason Day collapses on day two of the 2015 US Open

nd child, was at the course Friday.

“He gave me a heart attack there for a minute,” she said. “I think it’s encouraging that he wanted to finish. He’s like, ‘I don’t care, I’m dizzy, but I’m just going to finish.’

“I just asked him if it just happened, and he said it just happened. I’ve never seen it come out of nowhere like that. I mean, I saw him have it in Akron last year really bad because we were on the bus and he was like, ‘What is going on?’ He was like, ‘I swear the bus is moving right now,’ and I’m like, ‘It’s definitely not moving.’ And it was really bad then, but they did those maneuvers and it seemed to help.”

Day left the trailer Friday with assistance, then was taken away in a van. He later was shown entering a motor home on the course.

“I was glad we could get done,” Rose said. “At least he has a chance to recover for tomorrow, hopefully. I don’t know if this is one of those things that is 10 minutes or a day. I don’t know.

* Thanks to www.espn.com