Indianapolis - The Indiana Pacers head into Game 6 against the New York Knicks in unfamiliar territory.

Point guard George Hill is out with a concussion, NBA rules requiring him to pass a concussion test before he can play again. The Pacers have no idea whether that will come in time for tonight's potential closeout game. Officially, the team says Hill is day-to-day.

It's a sensitive topic around Pacers headquarters, where coaches and players remain hopeful Hill will be back on the court but are preparing as if he won't be around to help.

"Learning about it at the last minute was not ideal," coach Frank Vogel said. "But as a coach you prepare for those scenarios all the time. If someone gets hurt in the first minute of the game, it's the same thing, right?"

This is not the same thing, and that became evident late Friday afternoon when the NBA posted its concussion protocol on its own web site to clear up any potential discrepancies. Pacers spokesman David Benner instructed reporters to view the protocol because the team would not answer questions about it.

The policy states that any player diagnosed with a concussion must be held out of all activities until he is symptom-free at rest and they see no "appreciable" difference between the players' baseline test conducted before the season and the test after the injury.

Then the player must prove he is symptom-free as the level of exertion increases. Team doctors can then determine whether the player passes, a decision that must be discussed with Dr. Jeffrey Kutcher, the NBA's director of the concussion program.

The league has not established a timetable for how long players must sit out before returning because each injury is different. Sometimes, the recovery time is quick. Kobe Bryant, for instance, did not miss a game after breaking his nose and being diagnosed with a concussion in February 2012.

Hill did not attend practice Friday, and Vogel said he had not spoken with his starting point guard before the session ended. Hill is expected to undergo at least one more concussion test before tip-off against the Knicks.

"With or without George (Hill), the pressure has got to stay the same," Knicks coach Mike Woodson told reporters during a conference call. "We're preparing as if he is going to play. But the pressure has got to come whether he (Hill) is out there or someone else is out there."

The severity of the injury is unclear, too. Hill was injured early in Game 4 when he ran into Knicks center Tyson Chandler. He got up and looked a little wobbly after the collision, but did not leave the game and finished with 26 points in an 83-72 win.

That gave Indiana a commanding 3-1 lead in the best-of-seven Eastern Conference semifinals.

D.J. Augustin replaced Hill in the lineup Thursday and the Pacers struggled. They finished with 19 turnovers and wound up losing 85-75, a victory that got the Knicks within 3-2 and sent the series back to Indy for Game 6. Augustin played nearly 39 minutes and scored 12 points with no assists.

When asked what he would do Saturday if Hill couldn't play, Vogel replied curtly, "No comment," before explaining he didn't want to give away his game plan, a comment that drew chuckles.

If Augustin doesn't start, one possibility would be using All-Star Paul George at the spot. Vogel did that at times in Game 5 and George responded with a double-double - 23 points and 10 rebounds - and six assists.

"Honestly, I felt like having the ball in my hands put me in rhythm and the shots started falling for me," George said.

That's something the Pacers certainly need. They've only closed out three playoff series at home since 2000: last year against Orlando; in 2000 against Milwaukee in the first round and against New York in the conference finals.

And they don't want this chance to slip away regardless of who is healthy and who isn't.

"Here is where we really want to end it," George said. "If not, it will really be up for grabs."

The Knicks understand, too.

They've spent most of the series trying to rally after losing Game 1 at home, and with time running short on the comebacks, Woodson knows this is no time to play games. His lineup changes helped New York stabilize its struggling offense in Game 5, which they led from wire-to-wire.

With or without Hill, New York must play the same way Saturday at Indiana, where they're 0-4 this season, or they'll be heading home for the summer instead of going home for a decisive seventh game.

"Again, we've got to validate what we did last night," Woodson said. "That was a must-win; our backs were against the wall. They still are. When we lost Game 1, we knew right then and there that the only way to get out of this series was to go get one at Indiana and this is our last chance."