Brian Cashman's top priority of getting Jorge Posada and Mariano Rivera re-signed remains the same, but at least one of those Yankee stalwarts isn't inclined to make it that easy on the Bombers. Posada appears ready to make the Yankees work for his services, according to sources familiar with the discussions, as the five-time All-Star catcher plans to wait until he can hear offers from other teams before making a decision. Posada and the rest of his fellow free agents can begin fielding offers from other teams a week from today, though clubs are free to express their interest in free agents now without discussing money. The biggest sticking point for Posada may wind up being the length of a deal, as the 36-year-old is seeking a four-year pact, according to sources, who said the Yankees have internally discussed an offer of three years and $40 million.