Unless that was a really bad hamstring cramp for OG, he's going to be out for the rest of the this series. You can't rush a hamstring.
I know you never want to do it, but they might need to punt one of these games in Indy. I'm not saying to sit guys, but just roll the rotation minutes way back and see if someone steps in shit and can play for 6-8 minutes a game moving forward.
Burks is going to have to play now. McBride might have play near 35 minutes. Achiuwa might have to play 40 minutes. You're going to have to rotate Sims in for a bit too.
You held serve at home. The Pacers are just complaining about the refs the entire time. They're going to get their calls in Game 3 just like Philly did. If it's going that route, you have to do what is best for the series.