Girardi said he does not believe Severino will be intimidated by making his debut under the bright lights against the Yanks' long-standing division rival.
"There are no guarantees, but I saw his personality in Spring Training and the way he handled himself, and his professionalism," Girardi said. "I didn't think that he had fear and he wasn't overwhelmed in Spring Training like I've seen some of the pitchers.
"The first time they're there, it takes them a year, and then the next time you see them pitch well.