Phil Mickelson opened with a 4-over-par 75 and afterwards blamed spectators at Torrey Pines who did not shut off their cell phones.

Mickelson carded just a single birdie against five bogeys and sits eight shots back of co-leaders Russell Henley and Louis Oosthuizen.

“It’s part of professional golf,” Mickelson said. “You have to learn to deal with it. I don’t understand why you just can’t turn that little button on the side into silent.

“I probably didn’t deal with it internally as well as I could have or as well as I need to. It’s part of playing the game out here at this level. Certainly I didn’t do the best job of dealing with it.

“It did it the next three or four shots thereafter too, so it’s not like that’s the first time, it’s just that you had to ask three times.

“Again, it’s part of the game. It’s part of professional golf. You have to be able to let that go and not let it get to you and be able to kind of compose yourself and regather your thoughts and so forth, but they certainly didn’t do me any favors, either.”

The 51-year old, who won the PGA last month to become the oldest major champion, was unable to get into any kind of groove.

“I was fighting hard throughout the round,” Mickelson said. “I wasn’t really getting anything going, and I fought really hard, and then to let two bogeys slide on 6 and 7 when I really shouldn’t have, like they weren’t that hard of pars — you probably saw the disappointment there.

“Look, it’s part of this tournament, and I was able to go without any doubles, I just didn’t make enough birdies to offset it. Like I said, I’m hitting enough fairways to give myself chances, and I’m optimistic that I’ll put together a good round tomorrow.”