Tiger Woods has conceded that an "awful" day with the putter made it impossible for him to make a positive start to the US PGA Championship.

The former world number one, who is bidding to win his first Major for seven years, carded five bogeys on the way to a three-over-par round of 75 at Whistling Straits, and he could not hide his frustration when reliving his troubles on the greens.

"I hit it great today, but I made actually nothing," Woods, who is nine shots behind leader Dustin Johnson, told reporters. "It's probably one of the worst putting rounds I've had in a very long time. But I hit it good today, so that's about it.

"I just had no feel at all for the speed. It was awful. My speed was bad, hence speed determines line, so that was off. I either left them short or blew them by. I just didn't have the speed at all."

Woods, who is currently 278th in the world rankings, missed the cut at the US Open and the Open Championship earlier this summer.