Manager Joe Girardi has confirmed that he plans to use Posada, 40, as the team's DH for all five potential games against the Detroit Tigers, beginning with Friday's Game 1 at 8:37 p.m. ET on TBS.
"Our intent is to use Jorgie as our DH," Girardi said. "We will go with that, and you just play it out."
Posada's pinch-hit two-run single on Sept. 21 against the Rays was a highlight of an otherwise trying season for the lifetime Yankee, who was bumped from catching duties and struggled to adjust to his new role.
"There's not much I could control back then," Posada said. "Obviously, I started really bad and felt like I was doing some things well, but things happen. This is a different season right now. You play 162 games and you look forward. I think everybody in here does."
Yankees captain Derek Jeter, one of Posada's closest friends on the roster, said that Posada's experience as a piece of so many World Series championship clubs can prove invaluable at this point of the season.
"He's been part of it for a long time," Jeter said. "You know when they're up in those situations that he's not going to be intimidated by any situation he's in.
"He's comfortable; we have a lot of confidence in him. I don't really know if you say you're happy for him -- you just assume. He's always been there, you know what I mean?"
There is uncertainty ahead for Posada, who is wrapping up a four-year, $52.4 million deal and may be playing his final games in a Yankees uniform. He shrugged when asked if he will try to soak in the playoff atmosphere a little more in the days to come.
"It's day by day, right now, really," Posada said. "Hopefully, we can keep moving on. That's what you're here for, to play some fun playoff games. I think it comes down to, 'This is what you play for.' You get excited for this."