McIlroy has opted out of the European Tour's flagship event because he does not want to play four weeks in a row.
The world number three is returning from a three-week break to defend the Wells Fargo Championship in Charlotte.
"I am still working on it but I feel better than I did when I put the clubs away for a couple of weeks," he said.
The 27-year-old is the only member of the world's top five not to win a tournament in 2016.
Speaking to the Golf Channel, he added: "I'd got into a couple of bad habits leading up to the Masters and it's never really a good time to work on them - you are just trying to play golf and shoot a score.
"I took basically a full two weeks off from golf. I went home to Ireland for a week and then had a bit of a break; I was island-hopping for about 10 days, which was nice."
After the Wells Fargo at Quail Hollow, McIlroy will go on to compete in the Players' Championship and the Irish Open, where he will be tournament host at the K Club.
The four-time major winner will play in the Memorial Tournament in the United States a week after the Wentworth event in preparation for the US Open.
"The reason I took three weeks off after Augusta was that I'm not going to have more than a week off [at a time] until after the Ryder Cup in October," said the Northern Irishman.
