Miami ? Three weeks after angering NBA officials with their behavior at a league symposium, Miami Heat rookies Mario Chalmers and Michael Beasley reiterated their regret over starting their careers on such a sour note.

“My immaturity played a factor,” Beasley, the No. 2 overall selection out of Kansas State, said Wednesday during an informal interview session before an evening workout at AmericanAirlines Arena.

“It was just a mistake,” said Chalmers, the national-championship point guard from Kansas University who was drafted in the second round, “being at the wrong place at the wrong time, something we look back and we regret to the fullest.”

Beasley was fined $50,000 and Chalmers $20,000 by the NBA for violations at the league’s Rookie Transition Program in Rye Brook, N.Y.

The league cited the presence of improper guests in a hotel room where Beasley, Chalmers and former KU player Darrell Arthur of the Memphis Grizzlies were present.

The scent of marijuana was also present, although that was not cited by the league in the issuance of the fines, with privacy issues involved in the NBA’s substance-abuse policy.

Arthur also was fined $20,000, with Beasley given a steeper fine for initially refusing to cooperate with the league investigation.

Beasley acknowledged he was hiding in the room when hotel security initially arrived.

“I’m 19, so I kind of tried to be a kid and get away with it,” Beasley said. “It was kind of eating away at me, just to watch my teammate go through so much, and be basically hiding behind the lights. I just felt it was the right thing for my team, and just to stand by my teammate.”

Beasley was allowed to remain at the four-day seminar, unlike Chalmers and Arthur, who were immediately expelled and required to attend next year’s program, something Beasley will not have to do. The incident took place on the eve of the four-day session.

The league said there would be no suspensions attached to the fines.

“It’s a situation that’s over and done with. We put it behind us,” Chalmers said. “I think it’s helped me a lot, just being in that situation, learning from it, learning not to even be in a predicament like that, not to be in a situation like that. Other than that, I’ve been through a lot of stuff before and I’ve just got to get over it, get over the hump.”