World number two Rory McIlroy has revealed how the pressure of chasing the career grand slam means that he's not a nice person to be around during the Masters.

McIlroy needs to win at Augusta National to join Jack Nicklaus, Tiger Woods, Gene Sarazen, Ben Hogan and Gary Player in having claimed all four major titles.

And asked to name the first thing he thinks of when someone mentions the year's first major, McIlroy told Golf Digest: "Stressful.

"I am, ask anyone who knows me, a complete p***k in the week leading up to Augusta. But they understand and know that. It's a stressful situation."

McIlroy famously lost a four-shot lead in the final round in 2011 after collapsing to a closing 80 and knows limiting his mistakes is key to getting his hands on a green jacket.

Since 2010, the 27-year-old has had more double bogeys or worse at Augusta than any other player under 50, a key factor in shooting a round of 77 or higher in six of his last seven starts.

"If I can make a three on (hole) four and a four on 11 every day this week, I think I'll be okay," the Northern Irishman joked in his pre-tournament press conference. "I think I played those holes nine over par last year.

"Around here, don't take on too much. Actually I had a little conversation yesterday with Jack Nicklaus in Florida. That's what he said. He said to me, 'I took on too much a couple of times and it cost me a couple of green jackets.' I'm like, 'Well, you have six'.

"But he said it is a golf course that can tempt you. It can tempt you into doing a little bit too much.

"I cast my mind back to the 11th hole on Saturday last year where I'm in the pine straw on the left and I'm trying to hit this low hook around and catch the hill and trying to get it up onto the green and hit this heroic shot, and it goes in the water and I make a six.

"That's the last thing I needed. I was three or four over for the day at that point and I needed to hit it to the right of the green and try and make my up and down. Even if you make five, five is better than six; take the water out of play."