Michele Steele reports on smokeless tobacco being banned at some ballparks; and talks to some players to see how they plan to adjust. (6:58)

Fines from cities with new smokeless tobacco bans at ballparks won't be the only penalties violators could face, according to a senior Major League Baseball official.

"Players or anybody in baseball found to have violated a law are subject to discipline from the commissioner," MLB chief legal counsel Dan Halem told "Outside the Lines." "Smokeless tobacco laws are no different."

Halem said that, under Article XII of the five-year collective bargaining agreement that runs through this year, the commissioner could have "just cause" to discipline players for "conduct that is prejudicial or detrimental to Baseball" if they break the new tobacco laws.

A sign banning smokeless tobacco was posted this week on the concourse at Fenway Park. Michele Steele/ESPN

An MLB Players Association official told "Outside the Lines," on the condition of anonymity, "MLB would have a fight on their hands if they attempt to discipline players under the 'Just Cause' provision." The union did not accept a league-wide smokeless tobacco ban that owners sought in collective bargaining in 2011 and is expected to again oppose a ban in this year's negotiations for a new labor deal.

San Francisco, Boston and Los Angeles each enacted laws that ban smokeless tobacco in the cities' big-league ballparks and other sports venues beginning this season. The city councils of Chicago and New York recently approved similar prohibitions on smokeless tobacco for Wrigley Field, U.S. Cellular Field, Citi Field and Yankee Stadium. The state of California approved a similar bill for 2017 that would enact bans at three more MLB stadiums. With legislators in Toronto and Washington, D.C., reportedly considering similar laws, more than one-third of MLB's 30 ballparks could have smokeless tobacco bans in effect next year.

It's unclear how the new measures, which carry penalties for first-time violators of up to $250, can and will be enforced for players, managers, umpires and fans. Jess Montejano, a legislative aide to San Francisco Supervisor Mark Farrell, whose bill led to the city's ban, said there are no plans to post extra police at the Giants' AT&T Park, but that officers will write citations if they see violations.

Newly posted signs in the clubhouses and fan walkways at Boston's Fenway Park provide a phone number that anyone who sees smokeless tobacco use can call to alert security.

Outside the Lines: Smokeless Tobacco Ban "Outside the Lines" addressed the growing number of cities banning smokeless tobacco at major league ballparks on its March 27 show.

Boston Mayor Marty Walsh said players realize they are role models, so enforcement "will take care of itself, that will police itself."

Said Montejano: "We're in a situation where no team wants to be caught chewing." The Giants declined an interview request from Outside the Lines.

Advocates for the bans say the most recent data from the Center for Disease Control suggests young athletes are especially prone to imitate the players who chew or dip, even though tobacco use among big leaguers has declined over the years. According to the CDC, high school athletes use smokeless tobacco at nearly twice the rate of non-athletes and their rate of use increased from 10 percent to 11.1 percent between 2001 and 2013.

An estimated 25 to 30 percent of MLB players dip or chew, according to Matt Myers, president of the Campaign for Tobacco-Free Kids, which is lobbying for the bans. Because ballparks are workplaces and public places, said Myers, "It's entirely appropriate to restrict the use of a harmful substance in such a setting."

Critics acknowledge that smokeless tobacco is addictive and dangerous, but say the activity is legal elsewhere and doesn't infringe on the rights of others. They also question whether bans are an effective approach and whether government resources should be spent on such initiatives.

Dr. Alan Blum, a physician and founder of The University of Alabama Center for the Study of Tobacco, said, "If bans are so successful, why do major leaguers who've come from college or the minors -- which both have bans -- do it?"

"I probably have mixed emotions," said Cleveland Indians manager Terry Francona, who is often seen in the dugout with a mouthful of chewing tobacco. "I wrap gum around it," he said, "because I don't want kids seeing me with it.

"I love it, but I know it's a terrible habit and I don't want somebody to see it and think, 'Oh, man, that's cool, I want to be like him, doing that.'"

Joe Garagiola, the legendary broadcaster and former player who died this week at age 90, championed the education and treatment of tobacco-using players for two decades. When Garagiola, a former tobacco chewer, appeared before Congress in 2010, he pleaded with baseball's owners and players to rid the sport of the habit. But, he said, "Baseball can't solve the problem by itself. We need help."

While MLB and the MLBPA are diametrically opposed on the issue of bans, they are collaborating on treatment and cessation programs for players. In a joint memo sent to all teams last month to raise awareness of the local bans, players were offered access to a treatment expert and free supplies of nicotine replacement therapy products such as lozenges, gum and patches.

Said Halem: "Before you can ask people to quit addictive behavior, you have to put them in a good position to do so."

As for how MLB commissioner Rob Manfred will decide on possible penalties for violators of ballpark bans, Halem said, "It will be case by case, considering the number of violations, how severe and whether they're cooperative and engaged in cessation efforts -- the objective is to help them kick the habit."

ESPN content associate Christopher Caudle contributed to this report.