Collison had 17 points, nine assists and six rebounds in Game 1, a 104-99 Bulls victory. He was off to another good start in Game 2 with eight points and two assists before leaving with the injury in the second quarter.
"It's not going to be 100 percent perfect but the more movement I get the better it feels," Collison said before the game. "I'll pick my spots. I know where to be aggressive and not to be aggressive, but I'm not really concerned with that. [The Bulls] know you have an ankle injury so they're going to try to run plays against you. I'm aware of that, and I'll be prepared for that."
The Bulls' Derrick Rose said their plan was going to be the same with or without Collison.
"He's a great player, but really nothing changes," Rose said. "Especially not for us. But for them, I really don't know. A.J. Price, he stepped in and did a good job for them last time. Playing hard, playing aggressive, delivering the ball to people when they need it. He played well for them, but we will have to see."
Bulls center Joakim Noah was sympathetic toward Collison, who suffered the injury when he landed on a cameraman along the baseline.
"Overall, I think that it's unfortunate," Noah said. "Even though we're competing right now, to see Collison go down the way he went down because of a camera, with all the rules that the NBA has, I think that that's something they could do a little better, putting the cameras back a little bit.
"You never want to see somebody go down because ... and it's happening all the time. It's not like the first time this happens. A guy goes down in the NBA playoffs because of a cameraman? I don't think that's right."
The Bulls lead the series 2-0.
ESPNChicago.com's Nick Friedell and Mark Montieth contributed to this report.