It felt as though Bubba Watson was choosing his words very carefully when he described Pinehurst's greens as "unfriendly" yesterday.

The two-time Masters champion would not be drawn into labelling them unfair, though, even if they are about to pose the world's best players serious difficulties when the second major championship of the year gets under way tomorrow.

"No, they're going to be fair to somebody; the top 10 this week are going to be happy with them," Watson said with a smile. "The guy winding up holding the trophy is going to be happy and the lady who wins [the US Women's Open next week] is going to be happy with them.

"I wouldn't say unfair; I would just say that they're very difficult. I say they're unfriendly because, when the pin's tucked on the left, we're used to attacking that pin. Now, even with a wedge in your hand, you might be like 'you know what, let's go 30 feet over here to the right and not attack it.' So when I say unfriendly it's because they're trying to beat you, the greens are sitting there going, 'okay, here's the pin, you can hit it here if you hit the perfect shot'.

"More than likely most of these holes I'm hitting a four, five or six iron into. So those pins around the bunker or up on a mound are not really friendly. I don't think it's unfair, I think it's a different mindset of golf.

"I don't play chess but it's a chess match, you have to play to a certain spot and hopefully two-putt from 60 feet or from just off the green, get up and down to get your par and then try to attack on another hole."

Pinehurst No. 2 will play 7562 yards this week but is a par 70 with just two par 5s - one of which is 617 yards - and four par 4s of more than 500 yards. The last time the US Open was staged here in 2005, it played 7214 yards. "A par-70 being 7600 yards is very difficult with the shape of these greens," added Watson, who won his second green jacket in three years at Augusta in April. "You couldn't ask for a better golf course, but the greens are very, very unfriendly."

This tournament means more to one man than anyone else, though. Phil Mickelson summed up the task he faces in trying to complete a career grand slam by winning the US Open this week. "The expectations of me looking forward to this event, for almost a year now, and how much it would mean to me, makes it a challenge," Mickelson said.

Only Gene Sarazen, Ben Hogan, Gary Player, Jack Nicklaus and Tiger Woods have won all four major titles in their careers, an exclusive club Mickelson has the chance to join by completing the 'Lefty Slam'.

"It's a career goal of mine to win all four majors," Mickelson added. "I feel like the five players that have done that have separated themselves from the other players throughout all time.

"It shows that they have a complete game. If I'm able to do that, I feel that I would look upon my own career differently."