MIAMI — A contrite Mario Chalmers spoke out about his banishment from the NBA's rookie symposium today, acknowledging that he made an error in judgment but denying numerous reports that he was using marijuana.

The Miami Heat rookie guard, who helped Kansas win the NCAA championship five months ago, released an apology through the team to several parties, including NBA commissioner David Stern, Heat owner Micky Arison, Heat president Pat Riley, Heat coach Erik Spoelstra and the Kansas basketball family.

Chalmers was sent home from the event Wednesday after security at the resort where the four-day session was taking place found Chalmers and former Kansas teammate Darrell Arthur in a room with two women, and security officials detected the scent of marijuana. No drugs or drug paraphernalia were found, but even having guests in the room broke NBA policies, and the two rookies were banished by Stern.

"Everyone who knows me knows I am a good person and I pride myself on doing the right thing," Chalmers said. "I am embarrassed this happened. I broke the rules, but I did not smoke marijuana."

Chalmers and Arthur will have to repeat the class, which discusses the challenges of making the transition from college to pro ball, next year. Both could be fined up to $20,000 and still may face a suspension at the start of the season.

"I made a poor decision in putting myself in the situation that I did," Chalmers said. "It is a dream of a lifetime to play in the NBA and be part of the Miami Heat. I look forward to starting my NBA career, this was a one-time occurrence and it won't happen again."

On Thursday in Memphis, Arthur also denied using marijuana.

"About the marijuana, I didn't have any," Arthur told The Commercial Appeal. I didn't have anything to do with marijuana or anything like that. I'd like to clear that up. ... I used bad judgment by bringing the girls in and violating the rules. It was a bad mistake. I'm not a bad kid or anything. I just put myself in a bad situation. I want to apologize to the GM, the owner and all the fans. You won't hear my name in anything like this from here on out. It'll be straight and narrow from here."

Chalmers is expected to vie for Miami's starting point guard spot this season.

The NBA symposium is required of all newcomers entering the league and focuses on issues such as life skills, handling finances, the importance of character and image, the difference between NBA and NCAA game rules, legal matters and dealing with media.

Chalmers was drafted early in the second round by Minnesota and quickly traded to the Heat, who raved about his play in the Orlando summer league and signed him to a two-year deal.