No momentum for Mickelson at US Open
Mickelson, a four-time major champion who has endured five runner-up finishes in the US Open without a victory, was among the early starters in warm sunshine at The Olympic Club's Lake Course, where Tiger Woods, Jim Furyk and David Toms shared the overnight lead at one under.
Toms was due to tee off in the penultimate group alongside US qualifier John Peterson at 2:55 pm (21:55 GMT), while 14-time major champion Woods and 2003 US Open winner Jim Furyk were to tee off at 3:05 pm (22:05 GMT).
Mickelson found himself among the morning starters after scrambling to make the cut on Friday. His seven-under 36-hole total saw him safely into the weekend with one stroke to spare, but the American, who turned 42 on Saturday, said he didn't know if he'd have a chance to put himself in the title mix.
"It depends," he said. "I've got to play a good solid round ... I have to shoot three- or four-under par to have a chance for Sunday.
"It's out there, but it's very difficult."
Mickelson was slow out of the gate with a bogey at the par-four second. He pulled back a shot at the fourth, but was back to one-over for the day with a bogey at the sixth.
Angel Cabrera, who won the 2007 US Open at Oakmont a stroke ahead of Woods and Furyk, was gaining a bit of ground on the unforgiving Olympic course.
The Argentinian had three birdies with just one bogey to lie two-under for the day through 15 holes. That put him at six-over for the tournament -- seven shots behind the top trio.