Rory McIlroy was more concerned with implementing a putting tip from Dave Stockton than potentially losing his world No 1 ranking to Jordan Spieth today.

Spieth missed the cut but due to McIlroy's changing divisor, the Texan can still regain the No 1 spot later today if Jason Day doesn’t win this week and McIlroy finishes outside the top 10.

McIlroy had to finish with two birdies to shoot a level par 71 on Sunday in the Deutsche Bank Championship at TPC Boston.

But at two over par and far from fluid on the greens, he's making up the numbers, 15 strokes behind Henrik Stenson, who shot 65 to lead by one from Rickie Fowler on 13 under par.

“It’s not something I really worry about,” McIlroy said about the OWGR after another lacklustre round marked by average putting and another three-putt. “I’m just worried about trying to get my game in better shape so I can compete and try to win tournaments.”

McIlroy had one three putt and 32 putts in total on Sunday despite trying to fix a problem spotted by occasional putting coach Stockton, who texted McIlroy on Saturday and got a return call.

According to PGATour.com's Brian Wacker:

“He mentioned a couple things to me,” McIlroy said. “I probably putted a little better today ... I just need to go work on it. I just need to get back in the rhythm of it a little bit.”

That’s been easier said than done for McIlroy, who has played just seven rounds since returning from an ankle injury that caused him to miss more than a month of action.

What Stockton noticed was that McIlroy was moving his legs during his stroke.

“If you’re rotating, you’re going to come up and catch it low on the putter,” Stockton said via cell phone. “It won’t be a consistent stroke.”

The way Stockton fixed the problem in the past was by placing a club against McIlroy’s knee to prevent it from moving.

The rest of McIlroy's game mostly sharp, it’s a small fix that could lead to big results.

Last summer, McIlroy talked about focusing on two simple things: spot (basically getting the left hand to move toward a spot rather than focusing on the hole) and process (staying in the moment and making good mental decisions). The result? Two majors and a World Golf Championships title in the span of a month.

Still, the turnaround might take some time given the lack of competitive rounds under McIlroy’s belt the last two months.

“I went out there today and committed to them and putted a little better,” he said. “But there’s obviously a lot of room for improvement.”

McIlroy has lost six strokes to the field on the greens this week as Stenson, who made four birdies and an eagle two in an immaculate 65, has gained 1.5 shots.

Second placed Fowler, who shot 67, has gained six shots on the field, and 12 on McIlroy.

As for FedEx Cup leader Day, who can become world No 1 with a win, a two over 73 saw him slip to tied 25th, nine shots off the lead.