LA QUINTA, Calif. — Phil Mickelson hit his opening tee shot so poorly in morning rain and cold that he hit a provisional ball just to get in another swing.

He scrambled to par the hole and went on to shoot a 4-under 68 on Thursday in the CareerBuilder Challenge, leaving him four strokes back in his return from two sports hernia surgeries.

“I struck it horrible, but I scored out of my mind,” Mickelson said. “So, I’m very happy with it. My first round of golf was Saturday and I’ve been able to work out just the last two weeks.”

Lefty hooked his first tee shot into the trees at La Quinta Country Club, then reloaded and hit the provisional into the fairway.

“That next hole, the second hole’s an extremely difficult drive and I wanted to just get another swing,” Mickelson said.

Tour rookie Dominic Bozzelli shot a 64 on the Stadium Course at PGA West — the most difficult of the three courses — to top the leaderboard.