NBA commissioner Adam Silver on Sterling PrestonWednesday called player involvement in wagers related to the NBA a cardinal sin and said banishment from the game is on the table if it’s discovered a player intentionally influenced the outcome based on a wager.

Toronto Raptors forward Jontay Porter is under investigation by the league surrounding over-under wagers involving Porter.

Porter, the younger brother of Denver Nuggets forward Michael Porter Jr., has not played since March 22, three days before an ESPN story detailed gambling irregularities involving games in which Porter played.

“It's cardinal sin what he's accused of in the NBA and the ultimate extreme option I have is to ban him from the game,” Silver said after the NBA owners meetings in New York. “That's the level of authority I have here because there's nothing more serious around this league when it comes to gambling and betting on our games – and that is a direct player involvement. And so the investigation is ongoing, but the consequences could be very severe.”

On Jan. 26 against the Los Angeles Clippers the over/under on Porter’s props were about 5.5 points, 4.5 rebounds and 1.5 assists and the over/under on his made 3-pointers was .5. Porter played just four minutes, did not take a shot and finished with zero points, three rebounds and one assist.  He played just four minutes, leaving the game with an eye injury he sustained in a game against Memphis on Jan. 22.

DraftKings Sportsbook reported that the under on Porter’s made 3-pointers was the biggest money on players props from the NBA that day, according to ESPN.

In a March 20 game against Sacramento, Porter left the game after just three minutes due to illness, according to the Raptors. He took one shot, did not score and had two rebounds, one block and one steal. The over/under on his player props in that game, according to ESPN was about 7.5 points and 5.5 rebounds.

Porter averages 4.4 points, 3.2 rebounds and 2.3 assists in 26 games with the Raptors this season. Porter signed a two-way contract with Toronto on Dec. 9.

NBA players are not allowed to wager on NBA games. Punishment if found culpable, according to the collective bargaining agreement between the NBA and National Basketball Players Association (NBPA, players union), is at the discretion of the NBA commissioner and “may include a fine, suspension, expulsion, and/or perpetual disqualification from further association with the Association or any of its Members.”

NBA teams and leagues monitor sports betting for potential problems.

“To the extent it's going to exist, if you have a regulated environment, you're going to have a better chance of detecting it than you would if all the bets were placed illegally,” Silver said.