Rory McIlroy receives Pinehurst pointers from Jack Nicklaus in sitdown prior to U.S. Open

Rory McIlroy has picked the brain of a certain 14-time major champion over the few years that the two Nike golfers have been friends. With Tiger Woods sitting out yet another grand slam event after back surgery, however, the owner of two major titles sought the advice of the granddaddy of all major winners, Jack Nicklaus, ahead of this week’s U.S. Open tilt in Pinehurst.

“He’s been really generous with his time with me, offered any sort of advice that I wanted or needed. He’s been great,” McIlroy told reporters Wednesday about his two-hour sit-down with Nicklaus a week earlier in the Golden Bear’s Palm Beach office. “To have that at my disposal, it has to be an advantage in some way.”

Before the two gabbed about “everything -- business, golf, brand, the whole lot,” the host of the Memorial Tournament, which McIlroy kicked off two weeks ago with a blistering opening round only to stink up the joint on Friday and barely sneak into the weekend, sought an answer to the younger golfer’s wild scoring disparities.

“‘How the hell can you shoot 63 and then 78?’” McIlroy said Nicklaus demanded.

Good question, given that McIlroy ranks third on the PGA Tour in overall scoring average (69.74) but, according to Ryan Lavner, third from DFL in the second-round (73.5). Nicklaus encouraged McIlroy to “change things up in the middle of a round if it wasn’t going well.

“He’d make a swing change right then and there,” said McIlroy, who marveled at “the mental strength to be able to do that and trust what you’re doing.”

The 25-year-old from Northern Ireland, who has had a good season inside the ropes, racking up six top-10 finishes in nine PGA Tour starts, may be the oddsmakers’ favorite to win this week. But with Woods offstage for a second straight major and Phil Mickelson and his quest to complete the Lefty Slam headlining a star-studded cast, McIlroy enters this week’s U.S. Open out of the spotlight.

The runaway winner of two majors has had his share of off-course distractions, what with his very public breakup with Caroline Wozniacki, but he has kept a low profile since finishing T15 at Jack’s place.

“I’ve stayed off social media for the most part the last few weeks and I’m going to continue to do that for the foreseeable future,” McIlroy said. “I’m really enjoying my golf at the minute, and just making that the No. 1 priority.”

With all eyes on Mickelson, McIlroy has gone about his business quietly and with a focus on a game plan designed to conquer Ben Crenshaw’s revamped Donald Ross Pinehurst gem. He hoped that the strategy he had in mind required no Nicklaus-like mid-round fiddling and diddling.

“I’m going to adopt a really conservative game plan,” McIlroy, who won the European Tour’s BMW PGA Championship last month after his breakup, told David Dusek recently about an approach he had drawn up that would keep his driver in the bag more than is the aggressive golfer’s habit.

“Middle of the green, middle of the green, middle of the green,” McIlroy said of his mantra for the four days on the restored track that features a totally different type of rough from the thick, juicy stuff that traditionally lines U.S. Open fairways; wide-open fairways; and “turtleback” greens that will test the best of players’ short games.

“I think if your iron game is in really good shape, then you can hit the middle of those greens,” McIlroy noted. “Even if it’s a 30- or 40-foot birdie putt every time, you’re going to do really well. If you short-side yourself, you bring a really large number into play.”

While confirming on Wednesday that any approach to the middle of the green was “a really good shot,” McIlroy conceded that he may go after five flags -- “if they’re pins that are accessible, pins that you feel confident that you can get to.”

Other than that, he seemed to subscribe to the theory that Bubba Watson offered on Tuesday, when the reigning Masters champion said he would “lay back” off the tee to ensure he hit the fairways and stayed out of the weeds that lined the short grass.

To that end, McIlroy has rearranged his golf bag by ditching one of his four wedges and adding a 3-iron to hit off tees on some of the shorter par-4s.

“There’s going to be holes where you’re going to lay back,” he said Wednesday, noting he would put his 3-iron, which he can hit some 270 yards, into play on, among others, the par-3 sixth and the par-5 10th. He would approach the 620-yard No. 10 as a three-shot hole.

McIlroy, at 25, has matured before our eyes since his major debut at the 2007 British Open, when he shared a 42nd place finish. Since then, he’s collapsed down the stretch at the 2011 Masters, followed up that implosion with two masterpieces -- an eight-stroke domination of the U.S. Open field at Congressional Country Club, and a clobbering of his colleagues by the same margin at Kiawah in the 2012 PGA Championship.

The six-time PGA Tour winner has taken all that he’s learned from his ups and downs in grand slam events and come up with this week’s angle, which is long on strategy even if it means he’s shorter off the tee. McIlroy played practice rounds on the track last week and expected a demanding battle even without the usual U.S. Open-like rough.

Whether Rory can live up to his favorite status and steal the show from Mickelson remains to be seen, but he certainly had the script memorized.

“This is a really strong golf course which tests all aspects of your game, but the [upturned-saucer] greens are its defense with all those run-off and everything,” he said to James Corrigan. “They’re tricky and I think here, more than anywhere else, you have to play to the middle of greens.”