Tiger Woods has revealed that his game is slowly starting to improve ahead of the US Open, which begins on Thursday.

The American, who has dropped down to 195 in the world rankings, carded the worst round of his career at The Memorial earlier this month, but the 14-time Major winner is optimistic about his form as he continues to make changes to his swing.

The 39-year-old told reporters: "Sometimes you have to make a shift and I did. It's short-term suffering for long-term gain. At Memorial, I made another baseline shift, just like I did pre-Masters, and it's rough going through it. Obviously I've got to do it in front of the world and sometimes it's tough. I've got to suck it up and do it.

"The good news is I've done it before in my career, I know what it feels like, I know how tough it is to go through those rounds. But for me, I was very proud how I grinded out those first two days to make the cut at Memorial. And I decided to make another shift at it and obviously shot a high number. But it was a shift in a good way, because now I'm able to hit the ball like I am this week.

"When I've made changes in the past, I've struggled through it. I've come out on the good side. I had to make a commitment and I have, and things are starting to come together piece by piece."

Woods will play the opening two rounds at Chambers Bay alongside Rickie Fowler and Louis Oosthuizen.