With Molina sitting out a fifth straight Barry Zito start, the Giants had two hits off Shairon Martis a former Giants farmhand through seven innings and lost to the Nationals 6-3 on Wednesday afternoon, depriving them of moving five games above .500 for the first time since 2004.

On his 31st birthday, Zito kept the Giants close through six innings they trailed 1-0, but the Nationals rallied for three runs in the seventh and two more off Pat Misch in the ninth. Zito's next start is Tuesday in San Diego, and he's guessing Molina will be his catcher for the first time since April 16, especially because it follows an off day.

"I'm eager to work with Bengie. It's been a long time," Zito said. "I'm eager to get on the same page and keep it rolling."

Zito insisted the choice of catcher isn't a factor in how he pitches, though his record and ERA are superior in games Molina doesn't catch. Zito said it has more to do with how he's throwing on a particular day than who's behind the plate.

"It never mattered. On a good day, it doesn't matter who's back there," Zito said. "Those are things people don't really want to talk about because it makes it a little less of a story."

Steve Holm caught Wednesday because Pablo Sandoval's left ankle was still sore after he fell on the basepaths Tuesday. Sandoval, the third baseman, drove in the Giants' first run with an eighth-inning single, and Molina was the next batter, pinch-hitting for Travis Ishikawa.

Another time he pinch hit in a Zito game, Molina beat the Padres 1-0 with a 10th-inning ground-rule double.

This time, not quite.

"He just missed that," manager Bruce Bochy said, adding it "would have been a different game" had Molina homered.

Entering the game, Zito had the lowest run support among Giants starters and second-lowest in the majors to the Mets' Johan Santana, which might be related to Molina being out of the lineup for five of his seven starts.

Before Wednesday's game, Bochy acknowledged Zito is comfortable with both Sandoval and Holm. "If you give a guy a breather, I'd rather do it with the same pitcher," said Bochy, a former catcher who realizes the grind of catching and is trying to preserve Molina's legs.

On days he gets a breather, what about playing another position?

First base, Bengie?

"People would be surprised," he said. "I played first base in winter ball. We had other catchers - Junior Ortiz, Doug Mirabelli, Brian Johnson - so I played a lot of first base."

The last time, he said, was 2000.

"Being a former infielder, I think once you start getting ground balls, you get used to it," Molina said.

One member of the coaching staff said the Giants have no intention to have Molina play first, listing range as one of the reasons. Molina himself isn't thinking much about it, either. "For now, I'm a catcher," he said.

The Nationals had 12 hits, none by Ryan Zimmerman, whose hit streak ended at 30 games. He went 0-for-3 and was walked intentionally during a three-run seventh inning. The walk followed a wild pitch, which moved runners to second and third.

With the bases loaded, Merkin Valdez replaced Zito and gave up a broken-bat, two-run single to Elijah Dukes.