Boston Celtics point guard Rajon Rondo has been suspended for two games for throwing a ball at an official and striking him in the chest during Sunday's loss in Detroit, NBA executive vice president of basketball operations Stu Jackson announced Monday.

Rondo started serving his suspension immediately. He missed the team's 89-73 loss to Dallas on Monday night and will sit out against Oklahoma City on Wednesday.

"You're always disappointed when that happens," said Celtics coach Doc Rivers. "You should never put yourself in front of the team. But it's an emotional game. We can all agree that it was a pretty bad foul and a clear foul that wasn't called. At the time, we were getting our butts kicked and the frustration was high and it's a human game. I can guarantee you five seconds, 30 seconds after it happened, I guarantee you Rondo wished he could take it back."

Also out for the Mavericks game was Kevin Garnett, who missed his second straight game to attend to a family matter. The expectation is he could be back with the team in time for Wednesday's pre-All-Star finale in Oklahoma City.

Frustrated by a lack of a foul call on a third-quarter drive, Rondo flipped the ball at official Sean Wright, earning a double technical and automatic ejection. Rondo now owns a team-high seven technical fouls on the season, placing him near the top of the league in technicals.

"I don't want anyone to get thrown out of a game, but he did," Rivers told reporters in Detroit after the game. "I didn't see what happened, so it's tough for me to make a comment on it. I was actually looking down at a sheet of paper, so I missed it."

Asked if he sought clarification on why Rondo was ejected, Rivers said, "No, I didn't even ask. At that point, I didn't care to find out. I'll find out later. I wasn't worried about that to be honest."

Chris Forsberg covers the Celtics for ESPNBoston.com.