A scary incident occurred in the second round of the U.S. Open when Jason Day was walking toward the green on his final hole of the day. As he approached his shot, the number 10 ranked golfer in the world collapsed, as reported by Yahoo Sports.

Day stayed down for close to 10 minutes as the tournament's medical staff rushed to his aid. His wife, Ellie, also came running inside the roped to check on her husband's condition. After a while, Day eventually got back up to finish his hole, connecting on a bogey, and ending the round at even-par 70.

"I've got vertigo. I'll be OK," Day told Greg Norman of Fox Sports.

It was initially thought that Day had slipped on the grass that has proven to be a slippery proposition for fans, players, and caddies alike. But Day's agent later revealed that the golfer was diagnosed to have suffered with "Benign Positional Vertigo." Day is currently being monitored closely and is expected to compete in the final round of the tournament.

"He may have told Collin [Swatton, Day's caddie], but he didn't say anything to us," Day's playing partner Jordan Spieth said.

As noted by the Yahoo Sports report, after finishing the round, Day signed his scorecard and was driven to his motorcoach parked at Chambers Bay. He is currently at 2-under, and within striking distance of the tournament lead.

This was not the first time Day has had to deal with dizziness. Speaking to the Golf Channel, his wife said that he also had a similar incident back in 2010. Last May, Day withdrew from the AT&T Byron Nelson, complaining of dizziness during practice round. In August of last year, Day also withdrew from the WGC-Bridgestone Invitational due to vertigo-like symptoms.

Day's team said that, while the golfer has undergone sleep studies, there still hasn't been a definitive answer regarding the cause of his dizzy spells.