The 49-year-old DeFrancesco grew up in the Bronx as a Yankees fan.
"Thurman Munson was my guy," he said.
DeFrancesco said he should have more than a dozen family and friends in the stands. He is hearing from more and more of his old buddies every day.
"Former high school football coaches, teammates, baseball coaches, teachers, everybody," he said. "They better be wearing their Astros jerseys when they show up."
DeFrancesco, a former catcher, played eight seasons in the Minor Leagues for the Boston and Cincinnati organizations. He took over for Brad Mills, who was dismissed on Saturday.