It also was quickly evident that his game was a little off.
“My back is fine. My game was a little rusty,” Mickelson said after opening his Phoenix Open title defense with even-par 71.
“I threw away a lot of shots,” Mickelson said. “I made some careless swings. Hitting it in the water on 12 was just pathetic.”
Mickelson is seven strokes behind leaders Bubba Watson and Y.E. Yang, who shot 64.
Watson birdied four of the final six holes. The 2012 Masters Tournament champion had eight birdies and a bogey in the afternoon session.
“This golf course, if your ball-striking is good, you can shoot some good numbers here,” Watson said after hitting 17 greens in regulation. “Hit a lot of greens, didn’t make too many mistakes, didn’t miss too many fairways. Just played solid.”
Yang birdied the final two holes. The 2009 PGA winner also had eight birdies and a bogey, playing the back nine in 6-under 30 in his morning round.
Scottsdale residents Pat Perez, Kevin Stadler and Matt Jones were a stroke back at 65 along with former Georgia golfer Harris English, William McGirt, Greg Chalmers and Chris Kirk.
EUROPEAN TOUR: In Dubai, United Arab Emirates, Rory McIlroy turned in his lowest score in more than three years with 9-under-par 63 to take a two-shot lead in the Dubai Desert Classic.
McIlroy played bogey-free while playing with Tiger Woods, picking up six birdies and an eagle during a 10-hole stretch in the middle of his round. He easily upstaged Woods, who had 68.
Edoardo Molinari made an eagle on the par-4 second hole on his way to 65. The group at 66 included Stephen Gallacher, the defending champion who also played in the feature group with Woods and McIlroy.
McIlroy had his best score since a 63 in the Hong Kong Open in November 2010.
The 24-year-old was No. 1 in the world at this point a year ago, but went through a troublesome season adjusting to new equipment and coping with his first prolonged slump.
He didn't win a tournament until the Australian Open in December. In his 2014 debut two weeks ago, McIlroy finished one shot behind in Abu Dhabi, where he was given a two-shot penalty in the third round for not taking proper relief.
McIlroy said he was “very close” to playing his best and that this was “another step up from Abu Dhabi” the way he controlled his irons.