The Masters 2014: Phil Mickelson still nervous ahead of first major of the year despite his three previous wins at Augusta National

Mickelson already has three Green Jackets and could match Tiger Woods and Arnold Palmer with a fourth but admits his preparation has been unusually hampered

Phil Mickelson practices at Augusta National ahead of the 2014 Masters (Getty Images)

Phil Mickelson insists he is nervous about competing at Augusta National this week, despite having won three green jackets and recording 11 other top-10 finishes in the year's first major championship.

Mickelson broke his major duck in the Masters in 2004 and went on to claim the title in 2006 and 2010, the left-hander also winning the 2005 US PGA Championship and last year's Open at Muirfield.

But a combination of indifferent form and injuries means the 43-year-old is not as confident as might be expected about his chances of matching Arnold Palmer and Tiger Woods by claiming a fourth victory here on Sunday.

"I'm nervous about this week because I always like coming into this week with a win," Mickelson said.

"I like coming into this week being in contention a few times and having that confidence and experience to build on.

"But I have to give myself a little bit of slack because I have not been 100 per cent. Last week I felt great, which I was surprised by, because I had pulled a muscle in Texas and withdrew.

"Physically I feel great. The parts of my game, if I break them down, they feel terrific. But I haven't put them together this year. I haven't had the results to fall back on.

"I haven't experienced that pressure to feel comfortable in that environment and so I'm certainly nervous, because this is a week that I care about the most. This is the most special tournament and I have to rely on kind of past performances and past successes and past memories to build that confidence."

Fortunately for Mickelson he has plenty of such memories to draw on, while the lack of punitive rough allows him to display his wide array of recovery shots.

"What I love about this course is the lack of rough allows you a recovery shot," he added.

"The limbs (of trees) are higher and you always have a chance to recover and that frees me up to not have to play tight, because one bad shot doesn't mean you're going to lose a shot.

"You always have a place to miss it, even on 13 and 15 and 11. I feel a lot looser when I play here which is why I've played well for 10 years prior to winning it."