Rory McIlroy reacts on the fourth hole during Saturday's third round of the Masters

Augusta (United States) (AFP) - Rory McIlroy’s career Grand Slam bid is all but over for another year.

The four-time major winner probably will struggle just to extend his run of top-10 Masters finishes.

The 29-year-old from Northern Ireland stumbled to his second consecutive one-under par 71 in Friday’s third round at Augusta National, walking off on one-under 215 and eight strokes adrift of leaders after a closing bogey.

“It’s not as if I’m playing bad golf,” McIlroy said. “I’m under par for the golf tournament, but I’m just not enough under par. I just made too many mistakes.

“All aspects of your game have to be really sharp to have a chance to win and to score well around here.”

McIlroy needs only the Masters green jacket to complete a career Grand Slam, an every-major win feat managed only by Tiger Woods, Jack Nicklaus, Gary Player, Gene Sarazen and Ben Hogan.

“I saw Tony (Finau) shot six-under the front nine. I’m going to need something like that tomorrow to maybe have a chance,” McIlroy said, before sounding a more realistic tone: “I can play a good round of golf and finish the week on a positive note.”

World number three McIlroy was the oddsmakers pick when the week began after an impressive victory in last month’s Players Championship and seven top-10 finishes to begin the year.

McIlroy matched his Masters career low in last year’s third round on the way to fifth place, his fifth Masters top-10 in a row, but never looked to duplicate the feat this time.

“I just tried to play a good round of golf,” McIlroy said. “But I just haven’t been getting much out of my round. I’ve just been making too many mistakes.

“I’ve been making the birdies, and doing the things that you need to do around here. I’ve just been – if I’ve missed a green, I haven’t got it up and down or put myself out of position.”

Too many tee shots into the woods and missed greens proved McIlroy’s undoing.

“I’m hitting some good shots. It’s just about hitting the shots a little bit better,” McIlroy said.

“It’s not as if anything is glaringly obvious in terms of what’s lacking in my game. It has just been one of those weeks where I haven’t quite got the momentum that I needed to get.”

- Little errors, big woes -

McIlroy settled for early pars before a 32-foot birdie putt at the par-3 fourth, but drove into spectators to bogey the par-3 sixth and another bogey followed at seven.

His tee shot at the par-5 eighth – which he eagled Friday and birdied Thursday – went left into the forest and McIlroy swung his club in disgust then salvaged par.

At nine, McIlroy bunkered his approach and could only blast into the rough on the way to bogey.

“Missing it left on six. Put myself out of position on a couple of the par-5s, where I can’t go for the green in two,” McIlroy said. “Just little things like that where a different day could be a different result.”

McIlroy began the back nine with a birdie but made bogey at 11 for the third day in a row before escaping trees to birdie the par-5 13th.

An eagle from eight feet at the par-5 15th and 12-foot birdie putt at 16 revived hope but he needed a 14-foot par save at 17 and missed a 14-footer to bogey 18.

“The rough this year is… longer than it usually is and it’s just hard to get control of your ball out of it,” McIlroy said. “I just haven’t driven it in the fairway enough to have control going into these greens.”