WALTHAM, Mass. -- Boston Celtics coach Doc Rivers was fined $25,000 for public criticism of officiating, NBA executive vice president of basketball operations Stu Jackson announced on Thursday.

After Celtics center Kevin Garnett ran into early foul trouble during Tuesday's Game 2 loss, earning two whistles in an 18-second span early in the first quarter, Rivers voiced his displeasure in his postgame press conference.

"I thought the fouls on Kevin were horrendous and had a huge effect on us," said Rivers.

Rivers hinted during a conference call on Wednesday that his words might have raised the league's antennae.

"I didn't think I said much and that could be a problem," said Rivers. "Because all I basically said was, Kevin getting into foul trouble had a huge impact on the game. That's not criticizing officials. So I've just got to make sure I focus on our stuff."

Rivers signed a five-year, $35 million contract extension with Boston after the 2010-11 season.

Garnett was fined $25,000 earlier this season for his role in a dust-up with the Brooklyn Nets, while Chris Wilcox earned a $25,000 for an obscene gesture on the JumboTron during a game in Philadelphia.