Henderson was originally expecting the year's second major would cap an already-busy four-week stretch of golf for her but added another event to her schedule in late May after pulling out of the previous week's tournament due to illness.

The Canadian admitted the busy spell has not been without its challenges but wanted to get in the competitive reps in a bid to rediscover the form that saw her collect her 13th LPGA Tour victory in January.

"Playing a lot of golf, it does weigh on you a little bit, both physically and mentally," Henderson told reporters at Baltusrol Golf Club in Springfield, New Jersey.

"But I feel like I've been just trying to build energy and trying to get stronger every single week leading up into this week here."

Henderson will be one of 10 former champions in the 156-player field this week at Baltusrol where she will be seeking her third career major title and first since last year's triumph in Evian-les-Bains, France.

With four majors left in the season and her national open, Henderson is hardly losing sleep over her results over the last few months and feels her game is not far away.

"This is definitely a time to start peaking and start to be on the up, so hopefully that happens," said Henderson.

"I feel like, yeah, starting off the year on such a high has been a little bit down the last few months, but I feel like the game is right around the corner, and just staying patient to see the results."

Henderson will play the opening two rounds this week in the company of American world number four Lilia Vu and number 13 Ashleigh Buhai of South Africa.