Source: Phils pursue Polanco

The Philadelphia Phillies are targeting Placido Polanco as their next third baseman, according to a source familiar with their thinking. And they were making a "very serious" effort to sign the 34-year-old free agent Wednesday, the source told ESPN.com.

Before Wednesday, the Phillies appeared to be locked in on three potential free-agent third basemen -- Polanco, Adrian Beltre and Mark DeRosa. But talks intensified with Polanco's agents Wednesday, a day after his old team, the Tigers, declined to offer him arbitration.

Polanco is a Type A free agent, so the decision not to offer him arbitration means the Phillies could sign him without losing their first-round draft pick.

There were indications Wednesday that the two sides were discussing a three-year deal.

Polanco played for the Phillies from 2002 to 2005. And their mutual familiarity appeared to be a major force driving their pursuit.

Although Polanco has won two Gold Gloves at second base since the Phillies traded him to Detroit, he played 95 games at third with the Phillies. And the club seems to have no reservations about moving him back to third.

The Phillies declined the option on third baseman Pedro Feliz last month to see if they could find a right-handed hitting offensive upgrade who could help balance their left-leaning lineup. They envision Polanco hitting second behind Jimmy Rollins, a move that would drop Shane Victorino lower in the order.

Jayson Stark covers baseball for ESPN.com.