The arrests of two well-known NBA figures Thursday in a nationwide federal investigation into internal gambling and high-tech scam poker — especially a sitting head coach and former Finals Most Valuable Player — have roiled the league, from players to front offices to agents, sources told NBC News.

The arrests, particularly that of Hall of Famer and Portland head coach Chauncey Billups, altered the tenor of this week’s conversations around the NBA, whose new season had started only two days earlier.

The mood, a front office executive for one team said, went from fanfare to “fear.”

“Who else is involved?” the executive said. “It’s a nightmare for the league.”

Reactions to the extraordinary news spread quickly, ranging from surprise to anger at the league itself, according to five people who work inside or closely with the NBA, all of whom were granted anonymity because they were not permitted to speak publicly about the matter.

“Surprised they got caught,” a player agent said. “But not surprised, as [gambling] is happening everywhere.”

Terry Rozier was indicted as part of an investigation into insider sports betting. A separate investigation into what law enforcement officials described as Mafia-organized rigged poker games led to charges for Billups. Jones was named in both indictments.

“Shocking day,” Indiana Pacers coach Rick Carlisle, who is also the president of the National Basketball Coaches Association, said Thursday before a game. Carlisle said he contacted Billups and his representatives to ask how Billups was doing but did not hear back.

“This is a very serious situation,” Carlisle said. “The irony, I guess, from my perspective, was yesterday was a day when our general counsel came down and read us all the regulations on gambling and warned our coaching staff, our players, our support staff about all these different things.”

Billups’ attorney did not respond to a request for comment.

Jones, in addition to the rigged poker games, was also accused of disclosing privileged information to bettors about the injury status of a player before a game between the Los Angeles Lakers and the Milwaukee Bucks in February 2023. That player was LeBron James, according to multiple reports, though he is not named in the indictment or accused of any wrongdoing. Jones was also accused of telling the same bettors on Jan. 15, 2024, that another Lakers player would miss the game because of injury, before that knowledge was public. The only player fitting the indictment’s description is Anthony Davis.

Billups, while he is not named in the Rozier indictment, is seemingly implicated, however. The indictment refers to a person named “Co-Conspirator 8,” who is described as an Oregon resident who played in the NBA from 1997 to 2014 and has been a coach since 2021. (Billups was drafted in 1997 and last played in 2014, and he became a head coach in 2021.)

Co-Conspirator 8 is accused of giving bettors inside information about a Trail Blazers game in March 2023, when Billups was their head coach. Co-Conspirator 8 is alleged to have told another defendant in the case that Portland would be “tanking” the game and that several of the team’s players would be held out with injuries. Other defendants in the case are alleged to have used the information to place bets against the Trail Blazers.

The “fear” from the potential fallout, or expansion, of the investigations came after FBI Director Kash Patel said at a news conference that investigations into gambling continue and Christopher Reya, an FBI assistant director in charge of the New York field office, called the indictments “just the tip of the iceberg.”

The league has dealt with gambling scandals before. Jontay Porter of the Toronto Raptors was banned for life last year for violating the league’s gambling rules after a league investigation determined he had disclosed information about his participation to bettors for financial gain. He later pleaded guilty to conspiracy to commit wire fraud in federal court and is set to be sentenced in December.

Last season, the NBA said in a statement that it was aware of an investigation by the U.S. Attorney’s Office related to Rozier.

A culture of gambling has existed in the NBA for years, multiple people said. Inside locker rooms, it is not uncommon to hear discussions of a recent game of poker or bourré, a trick-taking card game similar to spades that is popular among basketball players. A longtime team employee said that wagering and the competition that fueled it were so pervasive that nearly every team flight he was on had multiple high-dollar games taking place at once, often one between players and another between coaches.

J.J. Redick, the Los Angeles Lakers’ head coach, who also played in the league for 15 years, once told a story on his podcast about nearly coming to blows with a teammate because of gambling. After he referred to bourré as the “greatest gambling game” because of how the pot can grow “exponentially,” Redick said “the closest I ever came to a teammate punching me” was over a card game on a team flight.

In January 2010, former All-Star Gilbert Arenas was arrested in violation of gun control laws after he and a teammate, Javaris Crittenton, took firearms to the Washington Wizards’ locker room as a result of a gambling dispute. Arenas has since said the dispute started over a game of bourré. (Arenas avoided jail time but was sentenced to two years of supervised probation in that case.)

A league source told NBC News it is not uncommon for players to separate into different groups based on their salaries. A younger player, for example, may not gamble right away with a superstar on a max contract. But as salaries have increased in the NBA — the league’s highest-paid player will make over $59 million this season — the stakes on team flights have only gotten higher.

Outside of flights, players also often set up with or are invited to high-stakes poker games, with cities such as Los Angeles and Houston cited as popular for gamblers, according to a source. (Arenas was arrested in July as part of a separate Justice Department investigation into illegal poker games in the Los Angeles area. He has pleaded not guilty.)

Redick, who has coached the Lakers since 2024, told reporters Thursday that the team had gone through meetings that day about the league’s anti-gambling rules.

“It’s obviously on the front of everyone’s awareness,” Redick said.

Although gambling and the NBA have long been intertwined, Thursday’s arrests put the league on a different type of alert, an agent said, because it involved not lower-level players but Rozier, who has made more than $150 million in his career, and someone with the stature of Billups, a former NBA Finals MVP who was inducted into the Naismith Basketball Hall of Fame only last year and is widely respected around the league. The Trail Blazers deferred comment to the NBA and announced that an assistant coach, Tiago Splitter, would assume head coaching responsibilities.

The NBA first investigated Rozier after it was alerted in March 2023 to what a league spokesperson later said was unusual betting activity related to his performance. Such bets on individual occurrences during games, not on the outcomes of the games themselves — called “prop bets” — have become extremely popular. Concerned that such bets could also give players incentives to manipulate their performances for financial gain after Porter was banished last year, the NBA last year persuaded sportsbooks to no longer offer “under” bets for players on 10-day or two-way contracts, who generally make the least amount of money.

Rozier’s lawyer, Jim Trusty, told NBC News on Thursday that Rozier had been “cleared by the NBA.” The league never went quite that far publicly, however, saying in January 2024 only that its investigation “did not find a violation of NBA rules.”

Asked at a news conference in July about the NBA’s investigation and whether he was comfortable with the findings, NBA Commissioner Adam Silver acknowledged that federal investigators “have more resources at their disposal than the league office does when we do an investigation.”

However, because many interpreted Rozier to have been cleared by the league, only to be arrested later, a high-ranking team executive said Thursday that he was concerned that “people will lose faith in the NBA’s ability to investigate these things.” The executive added that he, too, had become dubious about what the NBA’s investigatory arm would turn up from investigations it handles or outsources to outside law firms, such as the ongoing probe into whether the Los Angeles Clippers circumvented the salary cap.

“This thing is not about Terry Rozier or Chauncey Billups,” the executive said. “It’s about that we trust the NBA to uphold the integrity of what’s happening on the basketball court.”

The NBA said in a statement Thursday that it continues to review federal indictments and allegations, which it took “with the utmost seriousness.”

Billups was arrested less than nine hours after Portland’s season-opening season-opening loss at home, a game notably attended by the team’s current owner and a financier in the process of buying the franchise. Billups was asked whether the change in ownership added pressure to his job.

“I do the best I can,” he said, “and let the chips fall where they may.”