Rory McIlroy blamed putting woes for his disappointing start to the US PGA Championship and insisted he is satisfied with his play from tee to green.
A four-time major champion and the winner of this event in 2012 and 2014, McIlroy opened up with a four-over 74 at Baltusrol to sit nine strokes behind early leader Jimmy Walker.
The world number four endured misery on the greens, with 35 putts a key factor in his Thursday struggles.
"I'm happy with my game from tee to green. [I'm] driving the ball as well as I have, ever, I think," said McIlroy. "Iron play feels good. Just when I get on the greens, it's a different story.
"I'll need to try and figure it out for tomorrow [Friday]. You know, try to shoot something in the mid-60s and get myself back into it.
"First and foremost, I have to play a good round to get into the weekend. I think that's the first objective, and then go from there."
Elaborating on his struggles with the putter, McIlroy added: "I'm struggling with the pace. I think you saw out there, there was a couple of putts from quite a short distance that I left short.
"That's the thing that sort of surprised me all week actually. They look much quicker than they are. They look much quicker than they putt.
"It is good on the putting green. It's just a matter of getting it from the putting green to the course. I think it's more of a mental thing, as well. Maybe that's why I'm saying to be a little bit more assertive and not quite as tentative.
"I know my game is there, to keep giving myself chances. Hopefully I'm not shut out [on the greens] tomorrow."
Phil Mickelson, second to Henrik Stenson in The Open two weeks ago despite a stunning performance at Royal Troon, was four over through 10 holes but recovered much of the damage to card a 71 in the company of McIlroy and reigning champion Jason Day (68).
"I've been playing very well at the British [Open] and in my preparation, and to come out and hit shots like I hit those first 11 holes was very disappointing," said Mickelson.
"However, I'm proud that I hung in there, fought and got three back coming in. I'm in a position where I know I'm playing well. If I go out tomorrow and just play a good round, I think I can shoot mid-60s and get back in it and that's the goal."