By Cody Westerlund–

CHICAGO (CBS) — It was just Thursday afternoon that the Bulls seemed in full control of this first-round series with the Celtics, not only because of their 2-0 lead at the time but also because of how that advantage had been achieved. The Bulls’ dominance had come in many manners. They were the more physically imposing team, locked in on defense and with defined roles finally had the ball humming like they’d long envisioned but struggled with in the regular season.

That dynamic all changed Friday ahead of Game 3.

It was mid-morning when the Bulls revealed the news that point guard Rajon Rondo would be out indefinitely with a fractured right thumb. And then it was in the evening that the Bulls were dispatched quietly in a 104-87 loss to the top-seeded Celtics, whose series deficit now sits at 2-1 with Game 4 looming Sunday at the United Center after they looked more themselves in discovering their top offensive form that included 17 3-pointers.

Chief among the Bulls’ concerns is the indefinite absence of Rondo, who was injured in the third quarter of Game 2 and was told by doctors he’s likely to be out several weeks. In a Game 2 thrashing of the Celtics, the Bulls had 28 assists, including a franchise-record-tying 14 from Rondo. They had 14 total Friday night to go along with 18 turnovers as their young point guards struggled mightily. Starter Jerian Grant and backup Michael Carter-Williams combined for eight points on 3-of-10 shooting with three assists and seven turnovers in 38 combined minutes.

The Bulls offense went stagnant for long stretches, complicated by star Jimmy Butler’s off night of 14 points on 7-of-21 shooting without a trip to the free-throw line.

“Just having another coach on the floor,” Dwyane Wade said of what the Bulls missed with Rondo out. “You got a guy who’s been in so many playoff series, been in the Finals, won a championship — you can’t replace that. Our young guys will come in next game and be better, but we can’t look to replace what Rondo brings. His experience is unmatched from that standpoint. Just like every injury and every blow, it hurts the team in the moment, but we have to move past and we have to figure out a way with our young point guards and the other guys on this roster to just be better next game.”

The Bulls’ best lineups Friday were those without a true point guard. They included Butler and/or Wade splitting point-guard duties, Paul Zipser on the wing and and two big men down low. Using such a five-man unit for extended time may be prudent, but it’d likely come with the side effect of Butler needing to guard Celtics star Isaiah Thomas more when he already carries a large burden.

It’s just one of many hard questions coach Fred Hoiberg and his staff to consider with Rondo out. Asked whether the Bulls could move forward with Grant and Carter-Williams playing such big roles, Hoiberg responded that his staff would review film and evaluate over the course of Saturday.

“We get caught up in wanting to do a lot out there, which we normally do, and that’s OK,” Butler said. “As we tell Jerian and Mike, just play basketball. Yeah, nerves run into everything. You’re out there playing, you don’t want to make mistakes. But just lose yourself in the game, have fun and play hard.”

Cody Westerlund is a sports editor for CBSChicago.com and covers the Bulls. He’s also the co-host of the @LockedOnBulls podcast, which you can subscribe to on iTunes and Stitcher. Follow him on Twitter @CodyWesterlund.