Mickelson struggles in season debut, trails by 9

• By Will Gray
• Jan 17, 2013 7:02 PM ET

On a day when birdies were flying early and often in the California desert, few of them came Phil Mickelson's way.

Making his 2013 season debut at the Humana Challenge, Mickelson recorded just three birdies en route to an even-par 72 at La Quinta Country Club on Thursday, leaving him in need of a strong second round to have any chance of contending over the weekend.

"That was not what I was expecting, because I really thought I was playing well," he said after the round. "My timing was really bad. Hopefully I'll settle down and shoot a good round tomorrow."

After battling illness for much of the past two weeks, Mickelson was unable to practice much in advance of this week's event. The rust was apparent Thursday, as the southpaw struggled on a day where leaders Roberto Castro, James Hahn and Jason Kokrak all opened with rounds of 9-under 63.

Playing the same La Quinta course as Mickelson, Kokrak carded five birdies along with a pair of eagles during his opening round. Castro's round came on the Nicklaus Private course, while Hahn opened on the Palmer Private, which is the course players will encounter in Sunday's final round.

A winner last week at the Sony Open, Russell Henley picked up right where he left off in Hawaii. The former University of Georgia standout carded seven birdies along with an eagle in his opening round at the Nicklaus Private course, shooting an 8-under 64 to trail the leaders by one shot. He was joined on that number Thursday by Aaron Baddeley, Greg Chalmers and Doug LaBelle II.

A group of players at 7 under after the opening round includes Ricky Barnes and Patrick Cantlay, while Zach Johnson, Bo Van Pelt and Stewart Cink highlight a large contingent one shot further back, trailing the leaders by three after opening with 6-under 66s on Thursday.

Mickelson was not the only notable player to encounter issues in Thursday's opening round. Playing at the Palmer Private course, U.S. Open champion Webb Simpson carded a 2-over 74, while defending champion Mark Wilson finds himself tied for 154th in a 156-man field after opening with a 5-over 77 at La Quinta.