A study released in 2014 by the Professional Baseball Athletic Trainers Society estimated that as many as one-third of major league players used smokeless tobacco, long a staple of baseball culture. These days, observation of various clubhouses suggests that the figure might be a little high. Before recent games at Citi Field and Yankee Stadium, one team had at least four players with smokeless tobacco containers in the clubhouse; other teams had no visible usage.

Players are no doubt aware of the health risks of smokeless tobacco, particularly after the Hall of Fame outfielder Tony Gwynn died in 2014, at age 54, of salivary gland cancer. Gwynn began using smokeless tobacco in 1977, and he attributed his cancer to frequent consumption.

Nevertheless, a number of players said they viewed the new laws as an invasion of personal rights.

Mets outfielder Curtis Granderson does not use smokeless tobacco and says he tries to embrace a healthy lifestyle. But as a veteran leader on the team, which has had several smokeless tobacco users in recent years, he is critical of the ban in New York.

“There still isn’t 100 percent clarity in terms of who’s going to be enforcing it,” said Granderson, who also sits on the board of the players’ union. “Is it the Citi Field law enforcement? Is it going to be the police? Is it going to be the New York State Police? Is it going to be Major League Baseball? If someone in the dugout — like we have security there for our protection — if they see a player that’s using smokeless tobacco, are they going to slap them with a ticket at that time?”

One player who uses smokeless tobacco thought the law created an unnecessary burden for players who should be focused on baseball rather than the risk of becoming scofflaws.

“I do definitely look around,” said the player, who requested anonymity because he had played at Citi Field. “Like, are there any cameras on me?”