A team media relations assistant dragged his heel through the dirt of the warning track about 200 yards from where Tanaka was about to throw his first bullpen session in pinstripes and virtually dared any one of the more than 100 journalists from two continents to cross it.
"Line, line!," the man shouted whenever one of the professional gawkers, generally a Japanese TV cameraperson, inadvertently ventured into the forbidden territory.
That was moments after another Yankees official had issued detailed instructions about where reporters could and could not go during the brief workout, instructions that translated roughly to: "Don't stand anywhere that might allow you to see him throw."
Or, cause him to see you.
For a pitcher who came to the United States with one of the strongest resumes of any Japanese export -- Tanaka went 24-0 with a 1.27 ERA for the Rakuten Golden Eagles last season, led his team to its first Japan Series title, and has not lost a regular-season game since August 2012 -- the Yankees seem to be swathing him in bubble wrap.
The way they controlled Tanaka's first spring "workout" -- a session even he admitted was surprising in its brevity compared to the norm in Japan -- made you wonder what they were so worried about.
After all, if they feared Tanaka would be distracted by 100 or so reporters and camera people, what will happen the first time he pitches at Yankee Stadium, in front of 40,000 fans? Or at Fenway Park, before 35,000 enemies?
So far, he doesn't appear to be the slightest bit breakable. Tanaka is young (25), fairly large (a listed 6-foot-2, 205 pounds), easygoing and seemingly not fazed by the media attention, of which he certainly got plenty in Japan.
"Honestly, when I stepped out on the field today, I was very, very surprised how many media there were out there," Tanaka said.
Sandwiched between Hiroki Kuroda and Ivan Nova on the Yankees' four-headed bullpen, Tanaka appeared free and easy in throwing 32 pitches, none of which, manager Joe Girardi said, was thrown at full intensity.
"I didn't think he was trying to do too much," Girardi said. "I thought he had a good plan when he went out there today of what he was trying to do, and I thought he executed it."
No one would say exactly what that plan was, but at this point in spring training, the workout generally is considered successful when everyone gets through the session without screaming or grabbing an elbow.
All four of the Yankees starters came through unscathed -- CC Sabathia toiled virtually unnoticed on the fourth mound, did some rather low-intensity running, and then everyone broke for lunch.
Afterward, Tanaka was brought into the media pavilion, another highly controlled environment, to answer a few questions with the aid of his personal interpreter.
The highlights: No, he was not nervous in his public unveiling as a Yankee; no, he did not feel pressure to live up to his $155 million contract; and no, he does not particularly like to run.
That seemed obvious as Tanaka labored through four laps around the warning track, a total of approximately one mile, along with Nova and three other rookies (Sabathia and Kuroda invoked the veteran's privilege of passing on the run).
Asked what his lasting memory of his first day in Yankees camp would be, Tanaka said, "Probably what I will remember is the four laps that we did at the end. It was pretty hard."
A few questions and answers later, he again brought up his running when asked if all the media attention had made it difficult for him to focus on his work.
"Actually, no," he said. "I didn't feel that way. But just the running part, that was really hard for me today. I actually didn't know that I was going to run this much. I'm a little bit of a slow runner, but that part I really can't help."
Tanaka did seem spry enough getting from the mound to first base in fielding drills. He laughed his way through that, and seemed to enjoy the give-and-take with reporters even if he understood only a fraction of the English.
"As a player, I feel very honored to get this much attention," he said. "Some of the fans were cheering today and I was very happy to receive those cheers. It really feels like now I'm ready to go out there and start this whole thing. Everything is going to be a new experience for me, so I'm very looking forward to it."
The whole thing made you wonder about the Yankees' caution in handling Tanaka -- but then again he is a $155 million investment.
It also could be an effort on the part of the Yankees to tamp down some of the expectations regarding Tanaka, if only to shield him from a little of the pressure that at some point he will face.
Already, Yankees general manager Brian Cashman has told ESPNNewYork's Ian O'Connor that Tanaka projected as a "really solid, consistent No. 3 starter," -- an assessment he later disavowed -- and Girardi was careful to say that on Saturday, his eyes were on more than just Tanaka.
"There were three other guys throwing that I had an interest in, too -- CC, Kuroda and Nova," Girardi said. "So I spread my interest around. I paid as much attention to him as I did to every other guy."
Tanaka's teammates, however, apparently didn't get the memo, and they made no effort to disguise their enthusiasm and curiosity over their newest teammate.
"I'm excited to get a chance to see him throw," Sabathia said on Friday. "From everything I've heard, he's great, so I'm excited to have him on our team."
"Everybody's talking about the guy, so when he threw a bullpen, even I stopped to watch him," Nova said. "He's really good, I mean in the bullpen, anyway. I saw some videos of him pitching, too. I'm excited that he's here. It was a huge upgrade for this team."
Brian McCann, who caught Sabathia on Saturday, used the word "excited" a half-dozen times in regards to Tanaka. Francisco Cervelli, who caught him in the bullpen, said, "The fastball was really good. Two-seam. Some sliders were good, some were a little slow, but he is going to get it."
But what we do know is that however long he lasts as a Yankee and whatever he does in major leagues, a lot of eyeballs will be on him, all the time.
"He's going to get used to that," Cervelli said. "There is attention for a lot of people here, even me sometimes. He is not the only guy who makes $100 million here."