SAN FRANCISCO -- Preferring versatility over second-base insurance, the Giants agreed to terms with infielder Mike Fontenot on a one-year contract Monday and declined to tender contracts to infielder Jeff Keppinger and catcher Eli Whiteside, casting the pair into free agency.

Keppinger and Whiteside remain eligible to sign with the Giants, though it's unlikely they will. If Whiteside goes elsewhere, his defection will hike the number of Giants from the 2010 World Series roster who are no longer with the team to 10. The others are left-hander Jonathan Sanchez, right-hander Ramon Ramirez, infielders Travis Ishikawa, Edgar Renteria and Juan Uribe and outfielders Pat Burrell, Aaron Rowand, Andres Torres and Cody Ross -- a free agent who's likely to sign with another team.

As expected, the Giants offered salary arbitration to nine players. This group includes right-handers Tim Lincecum, Ryan Vogelsong, Santiago Casilla and Sergio Romo, third baseman Pablo Sandoval, outfielders Nate Schierholtz, Melky Cabrera and Angel Pagan and infielder Emmanuel Burriss. The Giants will try to reach compromises and avoid arbitration hearings with as many of these players as possible in an effort to remain within the prescribed $130 million payroll limit.

The Giants didn't have room to keep both Fontenot and Keppinger, prompting Giants officials to characterize Monday as the culmination of a debate over their skills. The "tiebreaker," as Giants vice president of baseball operations Bobby Evans said, was Fontenot's ability to play shortstop. Though Keppinger was Cincinnati's primary shortstop in 2008, Fontenot's 42 games at that position for San Francisco in the last two seasons was enough to impress Giants officials. They reasoned that having Fontenot to complement Burriss as a backup to shortstop Brandon Crawford was more essential than retaining Keppinger as an alternate for Freddy Sanchez, the oft-injured second baseman who has been recovering from a dislocated right shoulder.

Fontenot, 31, also has considerable experience at second and third base. Keppinger, 31, has played every position except center field, catcher and pitcher. But he's not considered to be as strong a defender as Fontenot, particularly on the infield's left side. Keppinger's .281 lifetime batting average, including last season's .277, eclipses Fontenot's .263. Fontenot also slumped offensively last season, batting .227 in 85 games after hitting .283 in 103 games in 2010.

Ultimately, defense trumped offense.

"It was a tough decision," Evans said. "But [shortstop] was the difference-maker."

Money could have been a factor in the Giants' decision. Fontenot's 2011 salary was $1.05 million, compared to Keppinger's $2.3 million last year.

Fontenot made small yet significant contributions as the Giants surged to the lone World Series triumph in their San Francisco history. Acquired in a trade from the Cubs on Aug. 11, 2010, he hit .340 with runners in scoring position (18-for-53) for San Francisco and Chicago that year, far exceeding the Giants' National League-worst .248 average in those situations.

Whiteside, 32, etched himself into Giants lore by catching Jonathan Sanchez's no-hitter against San Diego on July 10, 2009. He hit .218 in 196 games in three seasons as a Giant, including a slump to .197 in 82 games this year. Giants pitchers recorded a 3.30 ERA in 2011 with Whiteside behind the plate, only slightly higher than their overall 3.20 figure. But while Whiteside dealt with an elbow injury last season, Chris Stewart emerged as Buster Posey's top replacement and Hector Sanchez developed in the Minors.