Rajon Rondo, whose late-season resurgence helped push the Chicago Bulls into the playoffs and then a 2-0 lead over the Boston Celtics, is out indefinitely with a fractured right thumb.

Bulls coach Fred Hoiberg said Rondo suffered the injury in the third quarter of Game 2 on Tuesday while swiping for the ball and hitting the elbow of the Celtics’ Kelly Olynyk. Rondo and played through it, but X-rays later revealed the fracture, which won’t require surgery.

Rondo is wearing a cast to protect that injury and to immobilize a wrist injury that he’s been playing through and will be re-evaluated in seven to 10 days. Jerian Grant will start Game 3 on Friday night and Jimmy Butler’s regular role as primary ballhandler will increase.

“We’re going to miss him, the pace that he sets for the team, the leadership that he brings, and the way that he plays,” Butler said. “We’ve still expected to win. We know what we’re capable of. I guess we’re doing this for him now.”

But Rondo’s loss is significant. Beyond the 11.5 points, 10 assists and 8.5 rebounds he averaged in the first two games, his ability to play with pace offensively, guard Isaiah Thomas defensively and communicate at both ends as the team’s main floor general and film watcher are crucial to the Bulls’ attack.

“Everybody is going to have to be ready to pick up for what Rondo gives us,” Hoiberg said. “We can’t change our approach just because one of our star players is out. We need to pick up for what he gives us. And I’m confident our guys will do that.”

In the first two games, the Bulls’ net rating when Rondo played stood at plus-14.5. When he sat, it dropped to minus-5.4.

“He is obviously our No. 1 pace guy. He’s one of the best in the league. He’s been that way for a lot of years,” Hoiberg said. “We don’t want to change the way we do things, but at the same time we understand that it’s a little different dynamic with our team the way it is. The biggest thing is going out and continuing to get it done on the defensive end.”

Indeed, in the direct aftermath of the Game 2 victory, Hoiberg praised Rondo’s defense on Thomas. That alleviated placing that responsibility on Butler, who plays such an important offensive role.

“It is (a concern),” Hoiberg said of losing Rondo’s defensive presence. “Rajon’s experience in these types of settings is invaluable. To miss that now with him being out, most likely for the rest of the series, it does put some extra responsibility on some guys. Again, we’ve been through this. We had other guys that have had to step up in players’ absences. Dwyane (Wade), when he went out a couple weeks ago, we had guys step in and fill in admirably. It’s going to have to be the same with Rajon out now.”

Cameron Payne will be activated. Grant said he’s ready.

“My teammates have confidence in me,” he said.

But the biggest burden as the Bulls vie to become the sixth No. 8 seed to topple a No. 1 seed since the NBA expanded the playoffs to 16 teams in 1984 will fall on Butler.

“I’ve done it this season, so I’ve got to be pretty comfortable with it. I’ve done it a lot. I’ll be alright, man,” Butler said. “It’s not about me. We’ve got young guys that are stepping in. We’ve got to make sure that they’re comfortable. I’ve played enough minutes to where I’ll be OK. We want Jerian and Cam and whoever else may play to know that it’s OK to go out there and hoop, man. Play basketball. This is the reason that you’re here, to hoop. It’s the playoffs. This is what you wake up for every day.”