Rory McIlroy insists his much-criticised putting is good enough to secure a first Masters title and complete a career Grand Slam.

McIlroy ranked a lowly 140th in strokes gained putting on the PGA Tour last year and suffered an embarrassing five-putt during the second round of the AT&T Pebble Beach Pro-Am earlier this month.

However, the former world number one is confident he has what it takes to triumph at Augusta National and become just the sixth player to have won all four major titles.

"At Augusta you don't need to putt great, you need to not waste any shots, no three putts, hole everything inside five feet," McIlroy told BBC Sport Northern Ireland. "I feel good about Augusta, I know the golf course so well.

"You don't need to hole every 15 footer that you look at, you need to be efficient, just not to be wasteful.

"Speed is important and lag putting, they are big keys and I feel like I've started to get lot better at that, especially there because there is a lot of break and a lot of different slopes but I think I have it figured out."

McIlroy took a four-shot lead into the final round of the 2011 Masters before collapsing to a closing round of 80, but believes he will eventually get his hands on a famous green jacket.

"This will be my fourth go at it (achieving the Grand Slam), I have had three top-10s in the last three years and I played well, but just not played well enough," the four-time major winner added.