Harrington doesn't have a top-10 in nine PGA Tour starts this season.
The Irishman, who came into the season having won back-to-back majors and three of the last six, tied for 35th at the Masters last month. He said when he ends a successful season, he tends to tinker too much with his game.
'To be honest, I don't want to play like I did in the majors last year,' he said. 'I want to play better.'
Harrington said he spent the off-season trying too much to perfect his swing.
'I've just got to get back to playing golf,' he said. 'I've been addicted to how I am swinging. I'm analyzing everything.'
Sports psychologist Bob Rotella has been trying to get Harrington to focus more on getting the ball in the hole.