Hill received an MRI on his back Saturday, according to the team.
He was initially hurt in Game 1 of the Cavaliers' first-round series when Trevor Booker set a back screen on him.
Hill felt stiffness in his back between Games 1 and 2. He felt well enough to score 11 points in the first half of the Cavs' 92-90 Game 3 loss to the Pacers before his back "locked up," according to coach Tyronn Lue.
With Hill limited to just two points in nine minutes in the second half Friday, Lue shifted LeBron James and Jordan Clarkson to point guard rather than put the ball in the hands of backup point guard Jose Calderon.
"It's hard to try and put a guy in in the fourth quarter to try to say 'save the team' when he hasn't played that whole three quarters," Lue said of Calderon. "But that's part of the game, it's the playoffs. To put Jose in that tough spot, I didn't want to do that."
Calderon played nine ineffective minutes in the Cavs' Game 1 loss, but bounced back with five points in 13 minutes in Cleveland's Game 2 win before the DNP in Game 3.
If Hill cannot play, will Calderon get his number called Sunday?
"We'll see going forward," Lue said. "You might be seeing Jose."
Lue said that if Hill cannot play, that would be the only starting position he would change for Game 4 -- James, Kevin Love, JR Smith and Kyle Korver would remain in the first unit. Hill is averaging 8.7 points on 56.3 percent shooting (33.3 percent from 3), 1.7 assists and 1.3 rebounds in the playoffs.
The Cavaliers trail the Pacers 2-1 in the series.