HOUSTON -- Being 15 games over .500 and holding a 31/2-game lead in the NL West wasn't enough for Giants general manager Brian Sabean.
The architect of San Francisco's stirring run to its first World Series title since 1954, Sabean is once again shaking up his roster.
With infielders Freddy Sanchez and Miguel Tejada on the disabled list, the Giants acquired second baseman Jeff Keppinger, a Parkview grad, from the struggling Houston Astros for two Double-A pitchers on Tuesday.
San Francisco also called up Brandon Belt from Triple-A Fresno to relieve first baseman Aubrey Huff, who has tightness in his lower back.
Sabean hasn't ruled out additional moves, either.
''Without being harsh, this group just isn't getting it done,'' the GM said before San Francisco hosted the Los Angeles Dodgers. ''We need to somehow extend the lineup any way we can, and we think this is an upgrade.''
The Giants have had numerous injury problems in their infield this season. Sanchez is out indefinitely with a dislocated right shoulder and Tejada was placed on the disabled list Tuesday with an injury to his lower abdomen. San Francisco signed former Houston second baseman Bill Hall after Sanchez was injured, but Hall is on the DL because of a leg laceration.
Tejada, who has played primarily shortstop and third base, left Monday's 5-0 win against the Dodgers after straining his lower abdomen while trying to field a grounder in the third inning.
''We felt with the injuries we've had up the middle, (Keppinger is) going to give us some strength there, some versatility,'' Giants manager Bruce Bochy said. ''We needed some help there and Brian did a terrific job getting us a really nice player to help out.''
The 30-year-old Keppinger arrived in Houston in a March 2009 trade from Cincinnati. He is a career .284 hitter with 30 homers and 200 RBIs with the New York Mets, Kansas City Royals, Reds and Astros since his debut in 2004.
Keppinger, batting .307 with four homers and 20 RBIs in 43 games this season since his return from foot surgery, is looking forward to playing for a team in the playoff hunt. He's expected to bat in the No. 2 spot in San Francisco's order.
''I get to go to a team that's in contention,'' Keppinger said. ''This will be the first time I've ever actually been on a team that's been in first place or even with a winning record. It's definitely exciting and that's what you want when you play this game.''
Sanchez, sidelined since June 10, was transferred to the 60-day DL to make roster room for Keppinger.
The trade for Keppinger is reminiscent of the moves Sabean made in 2010 when he signed Pat Burrell to a minor league contract, traded for reliever Javier Lopez and picked up Cody Ross off waivers from the Florida Marlins.
All three played key roles in the Giants' championship run, something Sabean hopes to re-create this year.
Reports continue to circulate that San Francisco will make a run at New York Mets outfielder Carlos Beltran, and Sabean hinted he was working on a ''bigger deal'' last week before turning his attention to Keppinger.