Rory McIlroy sat nine shots off the club house lead at the The Northern Trust tournament in New York on Thursday.

American Russell Henley shot a six under par 64 on the first day in a round that featured no less than eight birdies and two bogeys.

McIlroy, whose season has been badly hampered by injury, said he would like to finish with a win before he takes a lengthy break from the game in October.

However, he has left himself with a mountain to climb following a patchy first round in America.

An up-and-down front nine featured three bogeys and three birdies, including a four-hole stretch between five and eight when he either earned or dropped a shot on every green.

Henley overcame his lack of local knowledge by playing conservatively and aiming for the centre of greens in a strong start in the first of the PGA Tour’s four FedExCup playoff events.

"I didn't really know what to expect," he said, following his first competitive round on the Glen Oaks Club course.

"I’m just not positive what’s up there," he said. "I got some notes but I’m really happy. Greens were really smooth, so almost made a couple (of putts) early and rolled in a couple of five-footers and then just felt comfortable for the rest of the day."

Henley, who won the Houston Open in April and made the cut in all four majors, led fellow American Scott Brown and Colombian Camilo Villegas by two strokes with half the field back in the clubhouse.

British Open champion Jordan Spieth made a decent start with a one-under 69, but McIlroy and Matsuyama struggled. World number two Matsuyama bogeyed four of his final six holes for 74.