PHILADELPHIA (AP) -- Placido Polanco is putting aside his Gold Glove and switching positions to have a chance at winning a championship.

Polanco returned to the Philadelphia Phillies on Thursday, agreeing to a three-year, $18 million contract.

The 34-year-old free agent won Gold Gloves at second base for the Detroit Tigers in 2007 and this year, but will shift to third base, which hasn't been his primary position since 2002. He replaces Pedro Feliz, who became a free agent after the Phillies declined his $5.5 million option.

"I always wanted to be here, I never wanted to leave,'' Polanco said. "One of the reasons I wanted to come back is because it's pretty obvious the team is committed to winning. And I want to win. That's it. They asked me if I was willing to play another position and I was like, 'Sure.' I can play third base. I played in college, in St. Louis and I also played some third here. I feel pretty confident about it.''

Polanco first joined the Phillies in the trade that sent Scott Rolen to St. Louis in July 2002. He hit .297 with 38 homers and 160 RBIs in parts of four seasons in Philadelphia. Once Chase Utley become the regular second baseman, Polanco's role was reduced. He was traded to Detroit in June 2005 for reliever Ugueth Urbina and infielder Ramon Martinez.

Polanco batted .285 for the Tigers last season with 31 doubles, 10 homers and 72 RBIs. He hit .341 and made the All-Star team in 2007.

"For him to come back to Philadelphia to change positions, it's just one of the things he's about,'' Phillies general manager Ruben Amaro Jr. said. "He's not only a tremendous professional and a championship-type player, but he's a championship-type person, and that's what we're trying to do here, bring championship-type people, both talent-wise and personnel-wise.''

Polanco gets a $500,00 signing bonus, $5 million next season, $5.25 million in 2011 and $6.25 million in 2012. The deal includes a $5.5 million mutual option for 2013 with a $1 million buyout.

"The Phillies were always my first choice,'' he said. "I played here, I know most of the guys here, I know the city. And they have a pretty good team that's committed to win. I thank all of the other teams that expressed interest in me, but the Phillies were always my first choice.''

Polanco is a .303 hitter with 90 homers, 579 RBIs and 71 stolen bases in 12 seasons.

He joins a potent lineup that features five All-Stars -- Utley, Shane Victorino, Ryan Howard, Jayson Werth and Raul Ibanez -- and former MVP Jimmy Rollins. He's an ideal No. 2 hitter, but that's been Victorino's spot in the order.

"I want to win and you look around and we have a lot of great players,'' Polanco said. "It seems like you could flip this lineup around and it would still be good, you know? Whatever Charlie wants me to do, I'd be more than happy to do it. I just know everyone here plays to win. Chase, Victorino, Rollins, Howard, everybody.''

The NL champions also agreed to a $750,000, one-year contract with infielder Juan Castro, who hit .277 with one home run and nine RBIs in 57 games for the Los Angeles Dodgers last season.

The 37-year-old Castro replaces utilityman Eric Bruntlett, who became a free agent. Castro made 19 starts at shortstop, eight at second base and two at third base, while also appearing in left field for two games.

Castro's contract includes a $700,000 salary next year, and the deal has a $750,000 club option for 2011 with a $50,000 buyout.

"In Juan Castro, we have a versatile guy who can play multiple positions and is coming off a year in which he swung the bat fairly well,'' Amaro said. "We're very happy to add him to our club, as he will give Charlie options.''

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.