The Knicks went big in Indianapolis — and lost big. Now embattled coach Mike Woodson is ready to admit his mistake.

The Knicks are expected to go back to small-ball tonight in looking for their season’s most giant victory in do-or-die Game 5 at the Garden. Carmelo Anthony will head back to his customary power forward position as he tries to save the season from becoming a disaster.

The Knicks, looking to become the ninth NBA team to rally from a 3-1 deficit, need three straight victories over the big and burly Pacers to secure an Eastern Conference finals showdown against the Heat. A Knicks trifecta, considering the way they have lost confidence all at once, seems as unlikely as LeBron James winning the mayoral election in Cleveland.

Woodson is expected to reinsert Pablo Prigioni into the starting lineup and take out Kenyon Martin, who started at power forward in Tuesday’s 93-82 Game 4 debacle at Bankers Life Fieldhouse. The big lineup of Melo-Martin-Tyson Chandler didn’t help their rebounding woes and certainly didn’t help their offense.

The Knicks were 16-2 with Prigioni in the starting lineup in the two-point guard alignment that began in Utah on March 18. The popular Prigioni, who could be playing his final game as a Knick tonight, logged just 3:26 off the bench as Woodson stuck with Jason Kidd, who set a record by going scoreless for his eighth straight playoff game.

Woodson had wanted to combat the Pacers’ size and was also influenced by Iman Shumpert’s iffy status because of his sore knee. Woodson thought Shumpert wouldn’t play and was set to replace him with Martin, who went scoreless in 28:54 and had just five rebounds. He was also playing with the flu and a possible wrist injury.

“I’m contemplating doing that,’’ Woodson said of his return to smallball. “That lineup has been great for us for a couple of months. I went away from it [Tuesday] night to go big and a lot of that was based on guys not being in practice and not too sure about Iman. That lineup has been good and there’s a strong chance we go right back to that lineup.’’

After practice, the struggling J.R. Smith huddled with Knicks executive John Starks and they spoke for about 10 minutes. Starks, who is in alumni relations, rarely attends practice, but these are desperate times.

The Knicks probably are concerned with Smith’s mental state after he took full blame for the Knicks’ collapse amid his massive shooting slump. Yesterday, Woodson tried to deflect the attention from Smith.

When asked about Smith’s bold declaration, Woodson said he is the one to blame and indeed has been outcoached by Indiana’s Frank Vogel.

“It’s not about all of that,’’ Woodson said. “Again, I’m the head coach. Blame it on me. I don’t look at it in that light. The bottom line is we’re all trying to do the right things to win basketball games. If we don’t have the slippage to start the series, we’re feeling pretty good about ourselves. But right now our backs are against the wall and my job is to get us out of this hole.’’