Stephenson was diagnosed with a bruised right hip and was listed as questionable to return but started the second half.
He was injured on a hard drive to the basket, twisted awkwardly in the air and made the shot but was called for a charge. The third-year player landed hard on his back and hip and needed help leaving the court. Stephenson replaced the injured Danny Granger in the lineup this season and averaged 8.8 points and 3.9 rebounds for the Central Division champions.
Indiana leads the best-of-seven series 1-0.