US Open 2013: Paul Casey expecting 'brutal' test at Merion ahead of 113th championship The defence is still on the greens, it doesn't matter how narrow you make the fairways, somebody will always find them. The defence is on the greens, where they put the pin positions and how firm they get it; the only reason the scores will be low is that we've had so much rain leading up to it. On his form he continued: "It's the first time I've had to qualify so I am taking the approach that I am just enjoying playing in another US Open and I worked very hard to get here. I'm hitting it very nicely; the putting when it's good it's 64 in the afternoon at Walton Heath and when it's not, it's the 74 in the morning. That's a beautiful example right there. Around six inches of rain have fallen on the course in the last four days, with more forecast on Thursday afternoon that could make a mockery of the USGA's insistence on not allowing preferred lies. The USGA have also maintained their policy of putting the top three players in the world in the same group for the first two rounds, with Tiger Woods, Rory McIlroy and Masters champion Adam Scott among the later starters. Woods is seeking a 15th major title five years after his last came in a play-off with Rocco Mediate at Torrey Pines, while McIlroy is looking for a return to the sort of form which saw him win the US Open in 2011 and last year's US PGA Championship by eight shots.