By Larry Fine

SPRINGFIELD, New Jersey (Reuters) - Jason Day, playing after just one day of practice at Baltusrol, kept it simple in Thursday's first round of the PGA Championship, hitting fairways and greens and sinking enough putts to join the hunt.

World number one and defending champion Day, who found 17 greens in regulation, shot a two-under-par 68 and said the time away from the course might have been a blessing.

"If you practice Monday, Tuesday, Wednesday, you could be pretty tired with how hot it was," the 28-year-old Australian told reporters.

"It was in the mid to high 90s (35 Celsius). You can get pretty drained pretty quickly."

Day's time away was not exactly serene.

The Australian, who had planned to take Monday off to rest following the Canadian Open, caught a bug from his kids and then on Tuesday had to take his wife to hospital after she suffered an allergic reaction.

"I'm glad I took Monday, Tuesday off, even though I'm a little bit under the weather," said Day, who sneezed his way through another hot day at Baltusrol.

"It was kind of a blessing really to come out yesterday, play 18 holes real quick and then get out of here."

Day said he happily accepts the trade-offs that come with life on the road with his family.

"That's part of having a family. Things aren't going to be perfect all the time. I enjoy having my family on the road," he said. "It's not the first time that the kids and myself and (wife) Ellie have been sick. It's not going to be the last time.

"It's speed bumps that you have got to try and slow down and get around. Come out and execute."

Day's score could have been better as he was not able to capitalize on many of the chances he gave himself on the greens with a conservative approach that had him hitting many three woods off the tee rather than cutting loose with the driver.

He said that had as much to do with his strategy at the majors as with his relative unfamiliarity with the course.

"It's probably a little bit more conservative than I usually am, just only because in major championships ... you have got to be patient, take your opportunities when you can and work yourself up to the lead come Sunday."

(Reporting by Larry Fine; Editing by Andrew Both)