Milwaukee will be without Bobby Portis for nearly the rest of the regular season.

The NBA announced Thursday that the Bucks forward had been suspended for 25 games for violating the league’s anti-drug policy. The team said Portis tested positive for the pain medication Tramadol, which was added to the banned list of substances in the last year. In a statement to ESPN, Portis’ agent said he was given the drug thinking it was Toradol, which is an approved pain medication for NBA players.

“I was dealing with an elbow injury and using an NBA-approved medication for pain and inflammation,” Portis said in a team release. “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.”

Portis’ suspension will begin Thursday night when Milwaukee faces the Los Angeles Clippers.

“This is a very difficult set of circumstances for Bobby and our team,” Bucks general manager Jon Horst said in the release. “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.”