MLB embraced gambling while trying to preserve its integrity. It’s a big bet.

So when he was asked this week what he thought about San Diego Padres infielder Tucupita Marcano receiving a lifetime ban for betting on baseball last season when he was a member of the Pittsburgh Pirates, his answer was as informed as it was blunt.

“You know, I’m going to be quite honest: [The betting] was dumb,” Martinez said. “It’s frowned upon. It has been. In spring training, we go through meetings. Every now and then, we have someone come through from MLB telling us that gambling on baseball is not allowed. It’s not. Why do it? Why take a chance?”

Behind him, in the news conference room under Nationals Park, dozens of BetMGM ads dotted the monitors, backlighting the irony of MLB’s current situation for the cameras. As clear as MLB’s message to players is and has always been when it comes to gambling on its games, its embrace of legal sports betting partners and the money they deliver is not only muddying moral waters but also drawing road maps to temptation in clubhouses around the country.

Since the Supreme Court’s 2018 ruling in Murphy v. NCAA allowed states to legalize sports betting, MLB — like many other professional sports leagues — has welcomed the influx of cash and eyes on the sport that gambling can provide.

Sportsbooks popped up not only around but inside major league ballparks. Online betting companies such as DraftKings and FanDuel started sponsoring game broadcasts, and betting odds started rolling across television screens. Diamond Sports, the beleaguered former Sinclair affiliate that is under contract to broadcast games for a dozen MLB teams, agreed to replace naming rights partner Bally Sports with FanDuel on those broadcasts starting next year, according to a person familiar with the deal.

Meanwhile, in the past three months, MLB has seen its two biggest gambling scandals in more than 30 years, including one that consumed its most pristine and important star. Los Angeles Dodgers slugger Shohei Ohtani’s former interpreter, Ippei Mizuhara, is facing a potential prison sentence after admitting he stole more than $16 million from Ohtani to pay off massive gambling debts. MLB has emphatically cleared Ohtani of any wrongdoing, and Mizuhara is not accused of betting on baseball. But MLB knows well that it takes far more effort to fill cracks in confidence than it does to create them.

“The strict enforcement of Major League Baseball’s rules and policies governing gambling conduct is a critical component of upholding our most important priority: protecting the integrity of our games for the fans,” Commissioner Rob Manfred said in a statement this week. “The longstanding prohibition against betting on Major League Baseball games by those in the sport has been a bedrock principle for over a century. We have been clear that the privilege of playing in baseball comes with a responsibility to refrain from engaging in certain types of behavior that are legal for other people.”

Indeed, players and coaches said this week, for all its new dealings with sports betting partners, MLB has never been clearer with players about the importance of not betting on baseball.

Posters hang on the walls of every home and visiting clubhouse — one in English, one in Spanish — that not only tell players not to bet on baseball but also include a massive QR code they can scan to learn more about why. The entire betting policy, word for word, is taped to the wall in every clubhouse. Major league and minor league players alike sit through endless spring training sessions to both educate them and provide MLB with firm deniability: Everyone knows the rules about betting on baseball, so there is no excuse for those who violate them.

“Not too long ago, we had to go through an online course. Guys are aware. There are signs everywhere in the clubhouse,” New York Mets Manager Carlos Mendoza said. “… It’s sad to see people go down like that, but I think MLB continues their efforts to keep everyone in the loop and educated.”

Those efforts, it should be noted, have never been designed to keep gambling out of clubhouses entirely. High-stakes March Madness pools with entry fees measured in the thousands are annual traditions. Fantasy football leagues seize all clubhouse dialogue by mid-September. Players are allowed to bet on any sport but baseball, and many of them do. Increased access to betting apps on smartphones and increased advertising for those apps do not cause players to throw common sense to the wind.

“They’re a lot more adamant about it now. The meetings in spring training are to the point where you’re like: ‘Okay, we get it. You can’t gamble on baseball,’ ” Nationals outfielder Joey Gallo said. “It’s definitely ramped up more now that it’s so prevalent everywhere. Gambling is just in your face all the time now. They’re definitely aware of that, pushing that more.”

Still, as the suspensions levied against Marcano and four other players this week proved, knowing the rules does not always mean following them. MLB has tried to account for that, too. One of its partners tipped off MLB to bets placed by the suspended players.

An MLB spokesman said the sport’s betting and compliance group maintains relationships with regulators across the country as well as more than 20 partnered sportsbooks whose contracts with MLB require they notify it of any questionable activity. MLB also employs two third-party integrity monitoring companies, U.S. Integrity and Sportradar, that monitor betting markets to flag suspicious activity.

But players are not the only people in major league clubhouses who have access to the kind of information that could help them or others win bets. Coaches, official scorers, umpires and even trainers have the power to affect outcomes, too.

“If you look at the Ohtani-Mizuhara thing, it reminds you: There are tons of people with access to the locker room and players — interpreters, agents, personal trainers,” said Stan Brand, the vice president of Minor League Baseball, who said he has long worried about the temptation minor league players might see in betting on baseball given their low salaries. “All of them are susceptible to being plied for inside information, which can be used to handicap the betting. That’s a huge vulnerability for baseball.”

A spokesperson for MLB said all major league and minor league umpires attend annual in-person or Zoom trainings about the rules around gambling and that all other non-player league and club personnel are trained in the topic when they are hired and regularly thereafter. Multiple clubhouse staffers — the “clubbies” who are hired in part for their discretion with players’ personal matters — said the importance of staying away from baseball betting and bettors is passed down as a nonnegotiable rule of their employment.

Television and radio broadcasters are often employed by the team or broadcast companies, so their training is less regular, though some are so uncomfortable with reading betting-related ads that they pass them along to colleagues. After one of its members was approached for information about awards voting that might have informed bettors last year, the Baseball Writers’ Association of America sent a letter to all of its members reminding them of best practices. The circles around clubhouses are not small, and everyone in them sees the tightrope MLB is walking as it tries to preserve the integrity of its games in an era when gambling has never posed a more accessible threat.

“You look at ESPN, you see we’re the underdog, we’re not supposed to score eight runs,” Gallo said. “Yesterday we were playing [the Mets’] Pete Alonso, and we were sitting here looking at [somebody on] TV saying: ‘Pete Alonso’s going to hit a homer today. Put money on it.’ You’re like, ‘What the f—?’ It’s weird. You’re about to be playing in that game.”

Ben Strauss and Gus Garcia-Roberts contributed to this report.