Celtics coach Doc Rivers just briefed the media and did not commit to a starting point guard for today's game against the Orlando Magic (1 p.m.), but Rivers admitted it was "doubtful" that usual starter Rajon Rondo would be able to play.

As a result, Stephon Marbury is positioned to make his first start for the Celtics.

Rondo sprained his right ankle in Friday night's win over the Cleveland Cavaliers and had "pretty bad" swelling, according to Rivers. The coach would not full commit to Rondo's absence, but all indications were that Rondo will not play.

"It's sore. It swelled up pretty bad," Rivers said. "I don't know right now [if Rondo will play]. I would say it's doubtful. We'll see."

Rivers acknowledged that Rondo's absence would limit the Celtics because Marbury "only knows about three plays."Still, given the team's ultimate goal - a championship - Rivers acknowledged that the additional playing time could benefit Marbury as he tries to integrate into the Celtics operation.

Said Rivers, "his will get him a little closer to April, as crazy as it sounds."

In other news, Rivers said answered with a succinct "no," when asked if Kevin Garnett would have been available if today marked the opener of the postseason. Garnett seems to be targeting a return to the lineup for next Sunday's game against the Milwaukee Bucks at the TD Banknorth Garden, though Rivers and trainer Ed Lacerte seem decidedly less optimistic.

Garnett, of course, has missed two weeks since spraining his right knee at Utah on Feb. 19. Garnett did not speak with reporters and was not in a communicative mood before today's game - "Nothing to talk about, I'm hurting," he said - and Rivers said the club is not interested in rushing him back.

At the moment, the Celtics obviously are fighting with the Cavs and Magic for home court advantage in the postseason, buit Rivers indicated the club would not risk the health of its players to accomplish that goal.

"Obviously we want to have home court, but we believe we can win on the road," Rivers said. "We're not going to start the playoffs with guys who are not healthy. We're going to do what we need to do to have all guys healthy at the start of the playoffs."

Finally, the Celtics learned today that Glen Davis' flagrant-2 foul against Cleveland had been downgraded to a flagrant-1, eliminating the possibility that Davis could have missed today's game against Dwight Howard and the Magic. As it is, he will start.