Watch Kevin Na display how difficult the US Open course is at Erin Hills if you stray from the fairways.
The world No 68 took to Instagram to show the problems players could have during the tournament in getting out of the rough.
“Erin Hills is a great design course but the fescue is almost unplayable,” he wrote. “[By the way] never found the ball. So don’t hit it in there. Straight hitters have a chance!”
He then added in the video: “We’ve got three or four yards of rough then we’ve got fescue. I throw a ball in there literally three yards and you’re lucky if you find your ball.
“It’s like a hazard. Every hole we’ve got this, every hole.”
Na tried to hit his ball out of the fescue on two occasions, and failed to move it twice before admitting he’d lost it entirely.
Hit play on the top of the page to see Kevin Na’s fescue trouble at Erin Hills