Professional athletes and coaches gambling through “legal sportsbooks” would be a major problem for these sports leagues, but it probably wouldn’t even be a crime anyway. So the FBI involvement is almost certainly related to other criminal activities related to this gambling.
The FBI is holding a press conference right now on FOX news.
Some of the people who have been arrested today are being accused of gambling on the NBA and specifically on themselves, which will get you banned for life from the NBA.
In the Terry Rozier case, legal sports books alerted authorities about suspicious bets being placed on play prop bets relating to Terry Rozier, the FBI went back and looked at one game that I heard about where Rozier pulled himself out of a game with an ankle injury, the person with all the suspicious bets cashed them all in.
Using legal sports books by professional athletes to bet on themselves or their team is illegal and will get you banned from the sport.