Phil Mickelson rues missed opportunities

The American is five shots behind German leader Martin Kaymer after a round which included three birdies and just as many bogeys at Pinehurst on Thursday.

Mickelson, a six-time US Open runner-up, said he had missed an opportunity to be among the leaders.

"There was some low scoring out there. Some good scoring, I should say. Not low. I'm never upset, anything off of par is usually a good start," he said.

"I didn't hurt myself. I had a chance to get three, four or five under today had I made some makable opportunities, but I didn't throw anything away on some of the short ones.

"Right now it's my driving.I didn't miss a fairway with the driver, and that's a big thing for me. It's an unusual thing for me."

Mickelson remains in a decent position, with his even-par round enough to keep him in a tie for 16th and just two shots adrift of second.

He believes he can play less than 'perfect' and still be a major challenger heading into the weekend.

"You never know how it's going to go off," Mickelson said.

"This golf course, I get a similar feeling that I get at Augusta in that I don't have to be perfect.

"I can miss shots, I can miss greens and still get up and down. It is challenging, there are difficult shots, but they are manageable and puttable, if you pull them off."