Charlotte Hornets forward Al Jefferson has been suspended for five games for a breach of the NBA's Anti-Drug Programme.
Jefferson, one of the leading power forwards in the league over the last five years, is currently sidelined with a calf injury and the suspension will not start until he is physically able to play.
The league has not specified a reason for Jefferson's ban, which could see him sidelined for the rest of 2015.
"I want to apologise to the Hornets organisation, our owner, my team-mates and my coaches for the poor decision that I made," Jefferson said in a statement.
"I know I have let people down, especially the Hornets fans that have been so supportive of me since I arrived in Charlotte two years ago.
"I am blessed to be able to play the game that I love for a living and I do not take that for granted. From the bottom of my heart, I am truly sorry, and I am committed to making smarter decisions in the future."
Jefferson was averaging 13.7 points and 6.4 rebounds per game, some way down on his career averages, before suffering his injury against Milwaukee on November 29.