Rory McIlroy and Jason Day make late mistakes at Deutsche Bank Championship

Rory McIlroy admitted he struggled with the pace of the greens at TPC Boston as he opened the Deutsche Back Championship with a frustrating one-under 70.

Making only his second start since returning to action following an ankle injury, McIlroy was within one of the lead before dropping shots at each of his final two holes as he ended the day five behind early pace-setter Brendon de Jonge.

The world No 1, playing in the tougher, blustery early conditions, bogeyed the 14th – his fifth – before balancing the books with an eight-foot putt for birdie at the 16th, and he got under the card with a two-putt birdie at the long 18th.

McIlroy then converted a towering iron to four feet at the third and added another birdie at the next, but he undid much of his encouraging work when he missed the green at both eight and nine and failed to get up and down. 

"I felt like I hit the ball very well," said McIlroy, who had 31 putts on the day. "These greens are probably the fastest I have putted on in a while.

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"I was hitting the ball a little bit too hard at times and under-reading them, I just need to adjust to that. I hit a lot of good putts that didn't go in, and that probably has to do with the speed."

Day putts dry up

Meanwhile, Jason Day continue his excellent form as he started with three straight birdies at 10, 11 and 12, and he picked up further shots at the second and fourth to open up a two-shot lead on five under.

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But the Australian pulled his approach to the next and bogeyed, and he three-putted the ninth to take further gloss off his round.

"I was making everything I looked at, and then it slowly dried up," Day said. "It was a very patient day. You can't get out there and be so disappointed. Once you're frustrated you're going to make some mental errors and it's going to be bad for you."

Jordan Spieth was looking to bounce back from handing the world No 1 ranking back to McIlroy after missing the cut at The Barclays last week, but he faces a tough task to avoid another early exit after stuttering to a four-over 75.

Spieth carded eight bogeys in an error-strewn round despite missing only one fairway, and he declined to speak to reporters as he headed to the locker room.