The Mets have been in contact with free-agent Ruben Sierra, and it's possible that the 40-year-old could join the team when rosters expand to 40 in September. Before his mother's health problems, Sierra and the Mets discussed a program in which Sierra would spend a few days in Port St. Lucie, then a couple of weeks with Triple-A Norfolk before joining the big-league club Sept. 1. Even if Sierra joins the organization at the minor-league level by Aug. 31, he will be eligible (as an injury replacement) for the team's postseason roster.