“I guess when I consider my playing career, I think of No. 17,” Boone said. “So when No. 17 was available with the Yankees, I was like, I’ll take that.”

Boone said there would be no subliminal reminders of what the Yankees are chasing this year. They will be among the favorites, along with the defending champion Astros, Cleveland Indians and Boston Red Sox, to reach the World Series.

Indeed, in the early days of spring training under Boone, there are no T-shirt slogans (like the ones Chicago Cubs Manager Joe Maddon ritually trots out) or new motivational signs (like the ones that dot many major league clubhouses). In fact, when asked last week if there was anything new about spring training this year, C. C. Sabathia said, “We’ve got different lockers — that’s about it so far.”

Boone has taken a relaxed stance in spring training: blowing bubbles, chomping on gum, a bat seemingly always in hand, and a Yankees cap tilted back on his head as he bounces among the workout stations. He wants his hitters to be “obsessed” with controlling the strike zone and his pitchers to be “aggressively attacking” the strike zone. But he will leave much of the reinforcement of those themes to his coaching staff.

“Certainly we have things that are going to be incredibly important to us,” Boone said. “There are certainly messages that we want to be able to drive home through our positional coaches. But as far as me saying I want to put an overall stamp on it, no.”

No. 28 Has a New Back

The Yankees, the first team to put numbers on the backs of uniforms, have a peculiar relationship with them.