He wore No. 42, and appeared lean and regal, and his mere presence in late morning on the back diamonds of Yankee spring training initiated calls of “Mariano, Mariano” from fans stationed behind the fences that encase George M. Steinbrenner Field.

Yet the first day of work for pitchers and catchers still elicited this question:

Is that Mariano Rivera?

On first glance, it sure looked like Rivera. But there was something different in his gait as he went through a 25-pitch bullpen session and fielding drills.

It was not overt — no dragging leg or dramatic limp — and you might not have noticed without intense scrutiny. But, of course, we are in the intense scrutiny portion of Rivera’s program since he blew out his ACL last May 3 and is the lone player in any major league camp born in the 1960s.

We intensely scrutinize because unique athleticism is in the very forefront of how Rivera climbed from poor fisherman’s son in Panama to Greatest Closer Ever. In the genus of closers, he always has been more balletic swan than fire-breathing Goose. His movements graceful, flowing, precise. That allowed him to repeat his delivery and, thus, pinpoint pitches like few men ever while retaining a quick-twitch genius on and around the mound.