SAN FRANCISCO -- For Sergio Romo, security didn't come in the form of a contract. He preferred the less tangible yet equally real security of having a true baseball home and familiar teammates. That's largely why Romo, 31, spurned apparently better offers in free agency to stay with the Giants on a two-year, $15 million deal.

Including the Minors, Romo has spent 10 years in the Giants' organization since they selected him in the 28th round of the 2005 First-Year Player Draft. Speaking in a conference call Monday, he confirmed that he received multiple three-year offers from other teams and hinted that at least a couple of them said they would let him compete for the closer's role. Romo lost that prized spot last year to Santiago Casilla.

"I have to be honest. That third year meant a lot to me," Romo said.

Ultimately, however, Romo couldn't sever his Giants ties -- which are close to unbreakable, being that he's one of nine players who have performed on all three of the franchise's World Series-winning clubs in the past five seasons. The others are Buster Posey, Pablo Sandoval, Madison Bumgarner, Matt Cain, Tim Lincecum, Jeremy Affeldt, Javier Lopez and Casilla.

Video: Romo on winning three titles, parade

"You want to go to a place where you're happy and excited to go to work every day," said Romo, whose accord with the Giants was leaked last week but didn't become official until Monday.

To make room on the 40-man roster for Romo, first baseman Angel Villalona was outrighted to the Minor Leagues.

Said Giants manager Bruce Bochy of Romo: "He's meant so much to our success. He knows all of us; we know him. I can't say enough about how he carried himself this year. I know we made a switch, but he was all about winning."

By some measures, Romo endured his worst season in 2014. Not only did he lose the closer's role, but he also recorded a 3.72 ERA, his second-worst in seven big league seasons, and allowed a career-high nine home runs.

Romo improved as the season elapsed. In a 23-game span, he yielded two runs in his final 19 1/3 regular-season innings. The right-hander also surrendered one run in seven innings across nine postseason outings.

"I think Sergio's resume speaks for itself, with what he's done in high-leverage situations," Giants general manager Brian Sabean said.

Romo owns a 31-21 career record with a 2.51 ERA. At 405 appearances, he ranks 10th and sixth, respectively, on the all-time franchise list and in San Francisco annals (beginning with the team's move west in 1958). His 78 career saves tie him with Frank Linzy for seventh all-time.

The Giants are expected to finalize right-hander Jake Peavy's two-year, $24 million contract Tuesday.