Giants general manager Brian Sabean frequently refers to signing free agents as a "clean" process, since it doesn't deplete the existing roster.

This offseason, Sabean and the Giants are likely to get their hands dirty.

Coming off a last-place finish in the National League West, their third consecutive sub-.500 season and their fourth year in a row without reaching the playoffs, the Giants have numerous roster needs. They often filled similar voids in recent seasons by raiding the free-agent cupboard, which proved to be a convenient way of building a supporting cast around Barry Bonds.

But with Bonds gone and only two veterans -- catcher Bengie Molina and right fielder Randy Winn -- assured of starting jobs, the Giants probably won't be able to load their nearly bottomless shopping cart on the open market alone. Sabean has repeated for weeks that he intends to actively pursue trades, especially since the Giants have a surplus of pitching to offer.

"There's no secret that we're probably going to have to cross the bridge and trade part of our pitching," Sabean said.

Several Giants could intrigue pitching-hungry clubs.

Left-hander Noah Lowry tops the list of potentially expendable Giants. Lowry finished 14-8 in 2007, reinforcing his reputation as a proven winner. But Lowry's "peripheral" statistics -- including 87 strikeouts and 87 walks in 156 innings -- might have suggested to the Giants that at age 27, he already has peaked.

Lowry's departure would open up a spot in the starting rotation for Jonathan Sanchez, another left-hander. Yet Sanchez also is vulnerable to being dealt. He's young (turns 25 on Nov. 19), live-armed (62 strikeouts in 52 innings) and can start or relieve.

Right-hander Kevin Correia impressed the Giants in the season's waning weeks by finishing 3-1 with a 2.54 ERA in eight starts. While establishing himself as a candidate to claim a berth in the rotation, however, Correia also may have enhanced his trade value.

Right-hander Brad Hennessey, a former starter, diversified his resume by collecting 19 saves. The Giants, whose Minor League affiliates posted the second-best record in baseball, also have a plethora of pitchers from their farm system who could sweeten a deal.

Don't expect the Giants to completely ignore free agency, however.

This is the franchise that signed left-hander Barry Zito to a seven-year, $126 million deal last offseason. It's also the same team that made arguably the best signing in history by luring Bonds in December 1992 with a six-year, $43.75 million package.

Hot Stove

Also, consider the Giants' numerous free-agent acquisitions in the last five offseasons: Zito, Molina, infielder Rich Aurilia, outfielder Dave Roberts and first baseman Ryan Klesko (2006-07); right-hander Matt Morris (2005-06); shortstop Omar Vizquel, catcher Mike Matheny and right-hander Armando Benitez (2004-05); outfielder Michael Tucker (2003-04) and second baseman Ray Durham, third baseman Edgardo Alfonzo and outfielder Jose Cruz Jr. (2002-03).

Three times previously, the Giants' biggest free-agent signing was Bonds, who they retained with contracts of varying durations. But club management already has announced that it won't re-sign the all-time home run leader. The Giants are more than willing to keep potential free agents Vizquel and third baseman Pedro Feliz. But Vizquel, who has been offered a one-year deal, wants a contract with performance bonuses that would guarantee a second year. Feliz appears inclined to test the open market and is unlikely to re-sign before Nov. 12, when the Giants' period of exclusivity with him ends.

Given the Giants' history, they're widely expected to enter the bidding for third baseman Alex Rodriguez, who would fill one of the two or three vacancies for a productive bat in the middle of the lineup. Although the Giants already have committed nearly $55 million to 11 players, they might have the economic flexibility to accommodate Rodriguez, who's expected to command at least $30 million annually. But Sabean recently called the prospect of signing Rodriguez "a reach" that would "hamstring" efforts to conduct business in future seasons.

Expect San Francisco to explore the possibilities of signing any of the top free-agent center fielders: Andruw Jones, Torii Hunter or Aaron Rowand.

"We are going to have to delve into some of those conversations," Sabean said.

Needing bullpen depth, the Giants will probably consider the likes of Eric Gagne, Shawn Chacon, Jorge Julio, Scott Linebrink, J.C. Romero and Kerry Wood.

"There might be a need for experience -- guys with a track record," Sabean said.

The Giants also could weigh the merits of pursuing closer Francisco Cordero if they decide that Brian Wilson would be better off serving an apprenticeship as a setup man.

Still, it's apparent that the Giants don't regard free agency as the quick fix it once was for them.

"We're smart enough to realize how thin the free-agent market is," Sabean said.