Injuries: Celtics may not win their rivalry.

The Boston Celtics received a boost ahead of Game 2 of the Eastern Conference Finals against the Indiana Pacers, with Xavier Tillman upgraded from questionable to available.

Tillman missed Game 1 due to personal reasons but will be back for the 8 p.m. game on Thursday at TD Garden. His return provides the Celtics with an additional reserve big man option off the bench, adding depth to their rotation.

Al Horford will continue to start, and Luke Kornet is expected to be the first big off the bench, but Tillman’s availability gives coach Joe Mazzulla more flexibility.

In other injury news, Kristaps Porzingis remains sidelined with a strained right soleus. While Porzingis is progressing towards a return, it is unlikely to happen until sometime next week, potentially during the latter part of the conference finals.

The Celtics managed to secure a dramatic win in Game 1 against the Pacers. Jaylen Brown’s crucial plays forced overtime, and Jayson Tatum’s heroics clinched the victory, giving the Celtics a 1-0 lead in the series. With the return of Tillman, the Celtics aim to maintain their home-court advantage in Game 2.