"She is in such a good place mentally. You don't want to tempt fate but she is finding the game very easy at the moment."
Ko always brought a strong composure and mindset with her game and she was striking the ball well and very confident as she worked towards her aim of a peak performance at this major.
She was in the sort of form Jordan Spieth brought to the PGA tour last year and which Jason Day showed in his victory this week.
"It is something when you play like that, you want to keep playing and she is in a great place at the moment," Leadbetter said.
The rough was up in her win at the Kia Classic but she hit plenty of fairways with her new driver and was at the top of her form for similar conditions at Rancho Mirage.
Leadbetter's coaching plan for this major was to keep Ko's "tires pumped up" and give her small tasks to concentrate on so her mind didn't wander. There was little point tinkering or tampering with her game now, it was more about repetition and psychology.
Ko had her "best ball-striking week ever" when she won the Kia but they were aware of how fickle form could be in golf. She was peaking for this major where her record was nothing special.
Listen to David Leadbetter talk to Martin Devlin:
"It is a course that should suit her," Leadbetter said.
Ko had gained an extra 15-20m in driving distance, her iron play was accurate, wedge play and putting was on song and her mental game in order. She was stronger, her clubs suited her and she had added a right to left draw to her game.
"She has just got a perfect game for the majors so hopefully this is going to be a really good week for Lydia."
"It's a challenge because there is always a temptation maybe we could do this or maybe do that, but we have got a plan and we are sticking to it and so far so good."
