CINCINNATI -- Center fielder Aaron Rowand was out of the Giants' lineup for the second night in a row Wednesday, largely because manager Bruce Bochy saw no reason to bench any of the outfielders who have started recent games.

Left fielder Pat Burrell is 5-for-12 (.417) since joining the Giants. Center fielder Andres Torres, who plays one of the outfield corners when Rowand starts, has been invaluable offensively and defensively. Right fielder Aubrey Huff, who also has played left, entered Wednesday with a .291 batting average and a .385 on-base percentage. Moreover, if Huff were to return to first base, Buster Posey, who began Wednesday batting .444 (16-for-36), would have to be benched, unless he played catcher.

And since Eli Whiteside received his usual start behind the plate with Jonathan Sanchez pitching, Bochy had no intention of asking Posey to catch.

Bochy said that he discussed the situation with Rowand, who's hitting .225 and is in a 7-for-44 skid.

"I don't know how long it will be before he's back out there," Bochy said. "It could be [Thursday]."

Or it could happen over the weekend, since Bochy is reluctant to subject Huff to the oddities of right field at AT&T Park. In that case, Torres or Nate Schierholtz would play right field and Huff would man left field or first base.

"We might have to gear a little more toward defense in our park," Bochy said.

Posey belts first big league homer

CINCINNATI -- Buster Posey established a personal milestone by crushing his first Major League home run in the second inning of Wednesday's 6-3 Giants loss to the Reds.

Following a two-out walk to Pat Burrell, Posey drilled the first pitch he saw from Reds right-hander Aaron Harang into the left-field upper deck at Great American Ball Park, giving the Giants a 2-1 lead. The drive, which traveled an estimated 439 feet, was the 77th upper-deck homer recorded since the park opened in 2003.

Posey, the Giants' most heralded position-player prospect in years, homered in his 18th game and his 54th at-bat as a Major Leaguer. He played seven games for the Giants in September last year and was recalled this season from Triple-A Fresno on May 29.

The Reds cooperated with the Giants in obtaining the home run ball for Posey as a souvenir. All the fan wanted in exchange was a ball autographed by Posey.

DeRosa to have tests for numb fingers

CINCINNATI -- Mark DeRosa wants to learn the source of the lingering numbness in his left hand before he considers undergoing surgery on the damaged tendon in his wrist.

DeRosa, who has left his Minor League injury rehabilitation assignment with Triple-A Fresno to be examined, will undergo a vascular test Thursday, which will include an ultrasound examination that could reveal what's causing the numbness. On Friday, DeRosa will be examined in San Francisco by a neurologist.

DeRosa, who signed a two-year, $12 million contract last offseason, began complaining of the numbness in the pinky and ring fingers of his left hand when he was placed on the disabled list in mid-May.

"We need to find out what's causing the numbness," head athletic trainer Dave Groeschner said Wednesday. "You can't say we're done until we know what's going on. It's hard to fix something until you know how it's broken."

Groeschner said that DeRosa's numbness has subsided somewhat but hasn't vanished, prompting skepticism that the infielder-outfielder's tendon issue is the cause.

"We don't want to have surgery on his tendon and [then] he has numbness in his hand every six months," Groeschner said.

Reds' Leake a little like Lincecum

CINCINNATI -- Comparisons between the Reds' Mike Leake and the Giants' Tim Lincecum aren't widespread, but certain parallels exist.

Like Lincecum, Leake is smaller than the average pitcher. The consensus is that the Cincinnati right-hander is about two inches shorter and a few pounds lighter than his listed dimensions of 6-foot-1, 190 pounds. Leake also shares Lincecum's youthful features, the kind that probably will force him to produce his driver's license or Major League player's identification card more often than necessary.

Moreover, Leake has followed Lincecum's path to success. Leake, Cincinnati's scheduled starter Thursday against San Francisco, is the first Red to start a season 5-0 since Santo Alcala in 1976.

Leake bypassed the Minors after being Cincinnati's first-round selection (eighth overall) in the 2009 First-Year Player Draft. Lincecum was 10th overall in 2006. Like Lincecum, Leake ignored presumptions about his size.

"You can't worry about that kind of stuff. It's out of your control," Leake said. "Especially with the Draft. He definitely should have gone higher than what he did. I either shouldn't have, or should have been where I was. That's just the stereotypical stuff that kind of bugs you a little bit. Some guys will take the 6-foot-5 guy over a 5-11 guy just because they think they'll break down."

Leake and Lincecum differ in pitching styles.

"As far as the velocity, I haven't been compared to him," Leake said. "There's nobody like him mechanically. He's a rare breed. He's struggling a little bit right now, but it's still fun to watch the way he works."