But while Posada tries to regain the strength in his strained right shoulder, he is technically considered the Yankees' backup catcher behind Jose Molina, though the team plans to do everything possible to keep Posada's arm idle and not risk a further setback.
Posada took a first step toward getting back behind the plate before Friday's game, making about 20 tosses on the field at Fenway Park.
"I'm not ready, but it feels better," Posada said. "I'm looking forward to getting going. It feels pretty good, but I can't catch right now."
Posada feels the injury only when he throws and not when he swings, which is helpful for the Yankees, who used him again as a designated hitter on Friday -- one day after he slugged a ninth-inning home run off the Royals' Hideo Nomo at Kauffman Stadium.
"I'm happy that I can [DH]," Posada said. "At least I'm hitting, not in the dugout and the clubhouse watching the game. It's tough to sit down and watch the game when you want to play."
Yankees general manager Brian Cashman said that there is no immediate timetable for having Posada catch a game again, but that it would likely not come during the Boston series. Cashman would not rule out having Posada catch against the Rays on Monday at St. Petersburg. He last caught on Tuesday at Kansas City, allowing four Royals stolen bases before being lifted, reporting his arm felt "dead."
"You treat the patient, not the MRI," Cashman said. "He's still going to have to get over the final hurdle of throwing. He's got to get back on the field, doing the job."
In the event that something happened to Molina, Posada would have to be called into duty. The club's emergency catcher is infielder Morgan Ensberg, who lobbied for the job after telling Girardi he caught in high school. Neither Girardi nor first-base coach Tony Pena, Girardi has joked, are eligible to help fill in.
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.