Rory McIlroy abandoned a three month putting grip experiment and finished birdie- birdie for an opening 71 in The Memorial Tournament in Ohio.

The 27-year old world No 3 changed to the left-hand low putting style for the WGC-Cadillac Championship at Trump Doral on March 3 but changed back at Muirfield Village on Thursday, insisting he needs more feel if he is to cope with the famously slick greens at Oakmont for the US Open in a fortnight.

Even though he won the Dubai Duty Free Irish Open at the K Club with the unconvential grip, he joked that he won in spite of his putting and explained that lack of touch was something he couldn’t contemplate at Muirfield Village this week or at Oakmont

“Conventional is what I’ve done my whole career,” said McIlroy, who had 29 putts in a 71 as playing partner Jordan Spieth had 26 but bogeyed his final hole for a 70 on a day when Dustin Johnson had just 24 putts in an eight under 64 to take the early clubhouse lead.

“I won the Irish Open a couple of weeks ago with 127 putts for the week, so I didn't putt particularly well. I think I had 32 putts the first three days and 31 putts on Sunday. So my ball striking was what won me that tournament.

“I knew I needed to make a change, and I felt like my pace wasn't really good with left hand low, especially going into this week, obviously, the greens are fast.

“But then going into Oakmont, the greens are so fast there, and you have to have so much feel and touch. I felt like just going back to conventional was going to give me the best chance here and obviously there.”

McIlroy began the Irish Open with the idea of sticking with the left-hand low method.

"Yeah, I definitely feel like it's been better," he said on May 18.  "If you look at my strokes gained stats, I went from 170th up into the top hundred since I started to do it, so I've definitely improved.

"But yeah, I feel like I needed to make a change and I'm going to stick with it because I feel like it's the right thing to do right now, but that doesn't mean to say that I won't change in the future. 

"If I feel like there's something that might work a little bit better, I'll try that, but for the meantime, I'm definitely going to stick with it."

Currently ranked 122nd for strokes gained putting on the PGA Tour, McIlroy lasted just four more rounds before opting to change.

He finished 51st forputts per GIR and 58th for putts per round in the Irish Open taking 32, 30, 32 and 33 putts in a brilliant ball-striking week.

The world No 3 changed his grip to right below left before the WGC-Cadillac Championship at Trump Doral on March, sticking with it for seven events.

"I feel like it's something I'm going to stick with regardless of what the outcome is tomorrow or this week or next week," he said at Doral. "I really do feel like it helps me put a stroke on it that I want to. It's a great feeling. I feel like it gives my putting stroke a bit more of a better rhythm, as well, a better flow.

"Look, if it doesn't work right from the get-go tomorrow, you're not going to see me on Friday morning putting conventional again. It's something I'm going to stick with for awhile."

Asked why he changed, he said: "I missed a couple of putts on Friday at Honda that I felt even before I made contact with the ball, that my right hand had -- and I missed it left. So it was, I need to do something here. Was sort of, you know, playing around with a few different grips on the putting green over the weekend. This one felt more natural to me because I've done it before and I do it quite a lot when I'm just practicing in drills, as well. I thought, why not give it a go."

He decided to change back last weekend when he was “messing around on the putting green” in Palm Beach. 

“Just went back to the grip and really trying to focus on the basics like setup and eye position and ball position and alignment,” he said. “So I feel like, if I can put good structures like that in place, there's no reason for me to go with anything but with what I've sort of had before.”

McIlroy had six birdies, three bogeys and a double bogey in his 71 and admitted that hitting two wedges inside 10 feet to set up birdies at the eighth and ninth, helped him “salvage" something from the day.

Spieth had just nine putts in his first eight holes before cooling off, much to the relief of McIlroy and Justin Thomas (77), who remembered how he closed with nine back nine putts to win the Dean and Deluca Invitational last Sunday.

“Justin and I said, walking off the 17th green, so the 8th hole, he had 18 putts for his last 17 competitive holes,” McIlroy said. “It's impressive, yeah. But no one shot or one part of the game is more important than the other. 

“A shot is a shot, whether it's a putt or a drive. They're all important. We get it done different ways, but we get it done. So I think that's the most important thing.”