SAN FRANCISCO — That visible circle in the back pockets of big leaguers — typically a sure sign of smokeless tobacco — might be far less common next season.

Players new to Major League Baseball won’t be able to dip next year without risk of penalty, a provision under the tentative five-year labor agreement reached late Wednesday.

“I think the smokeless tobacco ban is both logical and I am thankful,” Los Angeles Angels reliever Huston Street said in an e-mail Thursday night. “I understand choice, but choosing to die sooner is not one I support.”

It is possible more than the 12 current major league cities with laws either in place or headed that way will have tobacco bans by the start of the 2017 season. That’s what many health experts and advocates in the prevention efforts are hoping for, at least, though they certainly would have preferred a tobacco ban across the board for baseball to set an example for youth and the sport’s future.

“The new collective bargaining agreement reached last night by Major League Baseball owners and players takes a major step forward in removing tobacco from the game by prohibiting all new MLB players from using smokeless tobacco, like chew, dip and snuff,” said Matthew L. Myers, president of the Campaign for Tobacco-Free Kids. “Combined with the fact that 12 major league cities already have prohibitions on tobacco use at their baseball parks by all players and team personnel, baseball is now on a clear path to become tobacco-free in the very near future.

“While we had hoped for a complete prohibition on smokeless tobacco in baseball in the new agreement, this is a major step forward and represents the first time the players and owners have a made a clear commitment to fully eliminating smokeless tobacco use in baseball,” he said.

Right-hander Cal Quantrill , a first-round draft pick by the Padres this year taken No. 8 overall out of Stanford, isn’t sure what the ban will mean for prospects working their way toward the top. The son of former big league pitcher Paul Quantrill, Cal Quantrill doesn’t chew.

“It’s hard to say if there is less dipping, but I would say people definitely are more aware of the consequences,” said Quantrill, who pitched between the rookie level and A-ball in 2016.

“Sounds like a good start,” Giants head athletic trainer Dave Groeschner said of the ban. “Those players should be used to it as that is already in place in the minor leagues.”

With cancer concerns at the forefront since Hall of Famer Tony Gwynn’s June 2014 death at age 54 from salivary gland cancer complications following years of dipping, the dangers of long-term tobacco use have become a national issue for the national pastime. Gwynn’s family filed a wrongful death lawsuit earlier this year against the tobacco industry.

White Sox ace Chris Sale quit chewing after Gwynn died.

For the last five seasons, big league players were prohibited from carrying tobacco products, including tins and packages, onto the field when fans were in the ballpark.