From the moment Phil Mickelson set foot at TPC Scottsdale early Thursday morning, it was clear that the back pain that sidelined him last weekend was gone.
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 an even-par 71 at Scottsdale, Ariz.
After effortlessly hitting his opening drive 300 yards down the middle on the par-4 10th, Mickelson dumped a 90-yard wedge shot into the left greenside bunker. He blasted 10 feet past the hole and sighed in relief when his par putt slid in.
A few minutes later on the par-3 12th, Mickelson found the water hazard along the right side of the green. His chip from the fringe stopped about 15 feet short and he two-putted for a double bogey. He three-putted twice, once for par and another for bogey.
‘‘I threw away a lot of shots,’’ Mickelson said. ‘‘I made some careless swings. Hitting it in the water on 12 was just pathetic.’’
He was seven strokes behind leaders Bubba Watson and Y.E. Yang.
‘‘I got off to a poor start, played a couple over, and finished poorly,’’ Mickelson said.
Mickelson first felt soreness in his back two weeks ago in Abu Dhabi, and pulled out of his hometown event in San Diego after making the 36-hole cut at Torrey Pines. He flew to Georgia to see back specialist Tom Boers and was told his facet joints locked up.
‘‘It’s fine. Honestly, it’s no big deal,’’ Mickelson said. ‘‘It was a five-minute fix. I just have to be careful for a week or two as it heals up. It’s fine. Mobility is back. It’s just not a big deal. It happens every now and then. Last time was about four years ago.’’
European — Rory McIlroy took another step toward regaining his form Thursday with his lowest score in more than three years, a 9-under 63 while playing with Tiger Woods to take a two-shot lead in the Dubai Desert Classic.
McIlroy played bogey-free in ideal scoring conditions on the Maglis course at Emirates Golf Club, picking up six birdies and an eagle during a 10-hole stretch in the middle of his round. He easily upstaged Woods, who was five shots behind after a 68.
Edoardo Molinari made an eagle on the par-4 second hole on his way to a 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 from Northern Ireland 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.