'Scrappy' Rory McIlroy happy with 66 to open PGA Championship

LOUISVILLE, Ky. -- An opening round of 66 put Rory McIlroy three shots back of the lead at the PGA Championship at Valhalla Golf Course and he hit the clubhouse on Thursday in a defensive mood.

The 2014 PGA Championship winner on these same grounds, McIlroy was suggestively queried about leaving "a few out there," insinuating his 5-under-par first round could've been better.

"I don't know about that," McIlroy said. "I sort of felt like it was pretty scrappy for the most part. I don't really feel like I left many out there. I thought I got a lot out of my game today. Some good up-and-downs, the chip-in on 6. I had a little bit of a scrappy part around the turn there, but overall really happy with -- not really happy with how I played but at least happy with the score."

When McIlroy retraces similarities to his last major win, it's hard to ignore he started that tournament with a first-round 66. McIlroy followed with rounds of 67, 67 and 68 to beat Phil Mickelson by one shot at 16-under.

McIlroy might have saved his round, and more, on Thursday during a two-hole stretch with a scramble par on the 18th hole before banking a birdie off the flagstick on the start of his back nine at No. 1.

"It was huge. I could have easily bogeyed 18 and been back to even par, and then again, that ball on 1 could have hit the flagstick and went anywhere," he said. "I could have made bogey from that. Potentially being 1-over par through 10, I'm 2-under. So it's a three-shot difference. It's a big swing."

Rain softened the course which was evident early Thursday. McIlroy said he senses red numbers will be a tournament trend even if the greens become "a touch firmer" because the general take was Valhalla was very forgiving.

"It's soft. Greens are really soft, especially for the guys that played last week at Quail Hollow where the greens were particularly firm," said McIlroy. "You come to greens like this, second shots are easier. Chip shots are easier if you do miss the greens."