SAN FRANCISCO -- Acting quickly on their vow to strengthen their bullpen, the Giants signed left-hander Jeremy Affeldt to a two-year, $8 million contract Monday.

Affeldt, 29, became the first of 171 free agents to make a deal since the open signing period began last Friday. "They didn't mess around too much. That's what my agent, Mike Moye, and I were really impressed with," said Affeldt, who didn't sign with Cincinnati last offseason until Jan. 23 and wanted to avoid a similar delay. Affeldt added that the quality of the Giants' starters hastened his decision. "With that starting rotation, the bullpen won't get burned out," he said.

After a season in which their relievers tied for 14th in the National League with a 4.45 ERA and allowed the third-most home runs (62) despite pitching the fourth-fewest innings (487 1/3), the Giants knew that bolstering their bullpen was essential. So they turned to Affeldt, who drew interest from eight to 10 teams.

Signing Affeldt won't slow the Giants' pursuit of other relievers, although general manager Brian Sabean indicated that they'll focus on right-handers. "That'll be the next list we work off of," Sabean said, noting that the Giants have a full complement of left-handers in Affeldt, Alex Hinshaw and Jack Taschner.

Among free-agent right-handers, Bob Howry has drawn interest from San Francisco. Juan Cruz is also believed to be on the club's shopping list, although his agent, Barry Praver, refused to confirm that. And Affeldt endorsed David Weathers, his former Cincinnati teammate who served as a mentor and more. "That guy's one of my best friends, so I'm a little biased to that scenario," Affeldt said.

Affeldt brings several assets to San Francisco.

"He's characteristic of a guy who's coming into his own," Sabean said.

One quality is versatility. Though he'll probably fill a late-inning setup role, his background as a starter enables him to pitch multiple innings with relative ease.

Durability is another. Affeldt led Cincinnati with 74 outings last season, finishing 1-1 with a 3.33 ERA and recording a 2.23 ERA in his final 34 games. In 2007, Affeldt made a personal-high 75 appearances for Colorado.

Accuracy is a third strength of Affeldt's. In 78 1/3 innings last season, he struck out 80 and walked 25 -- a ratio of better than 3-to-1. That's a welcome trait for the Giants, whose 652 walks were the NL's second-most.

"We know how much the bases on balls hurt us," manager Bruce Bochy said.

It wasn't always thus for Affeldt, who struck out 281 and walked 178 from 2002-06 with Kansas City. His improvement began after the Royals dealt him to Colorado in a four-player trade on July 31, 2006.

Rockies coaches, said Affeldt, "felt I didn't pound the [strike] zone enough."

So he focused on refining command of his curveball. Meanwhile, he gained velocity, probably as a result of relieving full-time. With Kansas City, he made 142 appearances as a reliever and 42 as a starter.

Affeldt blossomed with Colorado in 2007, posting a 4-3 record with a 3.51 ERA. He made seven postseason outings for the NL champions, including appearances in all four World Series games against Boston. He accumulated three shutout innings against the Red Sox.

This year, opponents batted .260 and amassed nine homers off Affeldt, but those were largely results of pitching 41 games at hitter-friendly Great American Ball Park. Affeldt permitted seven homers and a .302 average at home, compared with two homers and .203 on the road.

Affeldt owns a 26-28 record with 18 saves and a 4.55 ERA in 360 lifetime appearances.