Major-league sources said Tuesday the Giants are negotiating with Juan Pierre. Pierre had 204 hits, 156 of them singles, and stole 58 bases in 78 attempts for the Cubs in 2006. However, one source said it would be wrong to assume that Pierre is the Giants' primary free-agent target for center field, as an ESPN.com report suggested. The club remains in contact with Gary Matthews Jr., Dave Roberts and Jay Payton to fill their need for a centerfielder who can lead off.