Phil Mickelson is not ready to give up on his home course.(Gross/Getty Images)

So that's why Mickelson was so frustrated on Friday after shooting 75 in the second round of the 108th U.S. Open that he has so eagerly anticipated. He will start the weekend 4 over for the tournament, as a result, and seven strokes off the lead.

"It was a tough day for me today," admitted Mickelson, who couldn't keep pace with playing partner Tiger Woods, who vaulted up the leaderboard with a 68, as the two entertained the bulk of the 50,000 spectators. "You can shoot a number, and I didn't hit enough fairways today. I've got to hit the balls in the fairway. When I do, I'm able to play the course effectively. I'm able to make some birdies, make easy pars. When I don't, it's been very tough."

For the second straight day, though, Mickelson hit just 6 of 14 fairways. He's done marginally better at finding greens in regulation, hitting 20 of 36, but needed 33 putts on Thursday and 27 in the second round.

Still, Mickelson, who started on the back, was just 2 over for the tournament as late as his 13th hole when he made just his second birdie of the day. Bogeys at Nos. 6 and 9, though, dropped him back to 4 over through 36 holes.

"I didn't get anything going," Mickelson lamented. "Made some good pars, and when I made a birdie, I followed it with a bogey. I didn't get the momentum of the round.

"It was tough to finish with two bogeys because I fought hard to keep it 2 over. I had some birdie holes with 7, 8 and 9 coming up. The bogeys at 6 and 9 hurt."

Still, Mickelson, who grew up playing the challenging municipal course that overlooks the Pacific Ocean, was hardly throwing in the towel.

Admittedly, the San Diegan has never felt completely comfortable at Torrey Pines since Rees Jones' 2001 renovation. In fact, all three of his Buick Invitational wins here came before the "Open Doctor" got his hands on the seaside layout.

As often as he could this year, though, Mickelson made the 15-minute drive from his house to practice and try to find a comfort zone. Maybe it will pay off over the final 36 holes.

"I'm going to come back tomorrow and try to get this thing back to even par," Mickelson said. "(I) should have a chance on the weekend. ... A good round tomorrow gets me in it for the Sunday, and that's the goal."