MILWAUKEE — The NBA has suspended Milwaukee Bucks' forward Bobby Portis for 25 games for violating the anti-drug policy, the team confirmed on Thursday.

The Bucks said Portis tested positive for Tramadol, a narcotic used to treat moderate-to-severe pain.

His suspension will begin tonight when the Bucks play the Los Angeles Clippers. Portis cannot play again until April 8 — the 79th game of Milwaukee's 82-game schedule — at the earliest. 

Portis’ agent, Mark Bartelstein, told ESPN on Thursday that the NBA player made an “honest mistake,” claiming in a statement that he “unintentionally” took the pain medication. Bartelstein said Portis thought he was taking a pain medication called Toradol, which is an approved medication he’s used previously. His agent claimed the Tramadol pill came from an assistant of Portis, who had “mistakenly” told the player that it was Toradol.

“This was, again, an honest mistake that was made because of the similarity in the names of the drugs and the fact they both serve a very similar purpose,” Bartelstein said.

Portis also said the violation was an "honest mistake."

“I was dealing with an elbow injury and using an NBA-approved medication for pain and inflammation,” said Portis in a press release acknowledging the violation. “During that time, I made an honest mistake and took a pain-reducing anti-inflammatory pill that is not approved. I feel horrible and recognize that I’m responsible for what I put in my body. From the bottom of my heart, I want to apologize to the Bucks organization, my teammates, coaches, family, and fans. I give everything I have on the court and will terribly miss playing games for the Bucks during this time. I will continue to work hard and be ready for our long playoff run. Thank you for your support. I appreciate it more than you know.”

Bucks General Manager Jon Horst also addressed the suspension.

“This is a very difficult set of circumstances for Bobby and our team,” said Horst. “He and the Bucks organization respect the NBA/NBAPA Anti-Drug Program and will accept what’s been handed down. But we 100% support Bobby. Together we will take this opportunity to grow and will have a better and stronger Bobby and Milwaukee Bucks team. He’s an integral part of who we are, a huge member of the Milwaukee community, and we look forward to his return.”   

Portis is averaging 13.7 points and 8.3 rebounds for the Bucks this season, playing mostly off the bench.

This story is developing. Check back later for details.