NBA

After missing OT loss, Smith says Knicks must finish Celtics tonight

DIFFERENT STORY: J.R. Smith wants to close the Celtics out at the Garden tonight and says the Knicks would have done the job in Game 4 if he hadn’t been suspended. (REUTERS)

J.R. Smith is back tonight and ready to elbow the Celtics out of the playoffs.

The Knicks lead the Celtics, 3-1, in the best-of-seven first-round series and they expect to close out Boston in tonight’s Game 5 at the Garden after failing to do so Sunday.

Smith missed Game 4 because of a one-game suspension for elbowing Jason Terry in the jaw. The Sixth Man Award winner claimed yesterday the series would have ended Sunday had he played — giving the Knicks their first playoff series win since 2000 — then the flaky shooting guard pretended he had never heard of Terry.

“I’m extremely [motivated],’’ Smith said in his first comments since getting suspended. “I can’t wait.’’

The Knicks don’t expect to revisit Boston Harbor until next season. Game 6 would be Friday in Beantown.

“It’s a must,” Smith said of Game 5. “We’re planning on not losing any games at our building. We’ve got to get this thing over as fast as we can so we can get [Jason] Kidd his rest, [Carmelo Anthony] his rest, and get prepared for the next series.”

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The Knicks would face the winner of Atlanta-Indiana,which is deadlocked at 2-2. Smith believes the Knicks would have posted the Sunday sweep if he suited up in the 97-90 overtime loss.

“Oh yeah, it’d be over,’’ Smith said. “I would’ve been playing golf today.’’

The Knicks would have secured a week off if a pressing Anthony played a tad better than his 10-for-35, seven-turnover horror show. Melo has his wingman back tonight and no excuses.

“Oh, we want to end it,’’ Anthony said. “We came this far, did our job at home, got one on the road. We have an opportunity to end it here on our home court. It’s a special moment. It’s a very special moment for us as a team, for us as a city. As an organization, to do something special like that here on our home court. ”

Knicks coach Mike Woodson brimmed with confidence, too, yesterday.

“We’re in perfect position for our franchise and fans to get the job done so we can move on to the second round,’’ Woodson said. “I feel good about our chances. I’m hoping we can get everything finished off so we can get ready for Round 2.”

Smith, who played 80 of 82 regular-season games, missing only the final two to rest, has become the Knicks’ most indispensable player — the second sniper making it easier for Anthony.

The Knicks’ newest star claimed he didn’t know of the Celtics’ former Sixth Man of the Year, Terry.

Asked about Terry’s Game 4 overtime heroics, Smith deadpanned, “I don’t know who that is.’’

Is he concerned Terry might try to bait him tonight in his return?

“Who’s that?,’’ Smith said blankly. “I don’t know who that is. I’m sorry.’’

There have been suggestions on an earlier possession, Terry hit Smith in the groin area.

Smith seemed to confirm he took a low blow.

“I was [hit],’’ Smith said. “It don’t really matter. Me and my teammates were the only people who suffered from it. Nothing we can do about it now.’’

Smith left Boston Sunday morning and watched the game from New York.

“I wasn’t on the golf course,’’ Smith said. “I watched the game to see what happened. I wasn’t pleased with it. My teammates weren’t either. We got to make up for it [tonight].”

Anthony said he is thrilled to share the spotlight with his former Denver teammate. Anthony shrugged off criticism he shot too much Sunday because he refused to trust his teammates.

“We missed him,’’ Anthony said. “We miss his play off the bench. We miss him just being out there on the court with us — what he’s brought to our team this year. No lie, we missed him.”

Asked what he’s learned from the experience, Smith said, “Don’t throw elbows.’’

The Celtics view Terry as key to extending the series. The dueling sixth men appear primed.

“He’s going to come out and obviously be tough, aggressive, looking to be the spark for them,” Terry said. “But we’re just resilient, and it’s going to be a great game. I can’t wait to go.”

Woodson said he had a “major discussion’’ with Smith before he left Boston.

“It’s very important to have him,’’ Woodson said. “We missed 18 points the other night and still put ourselves in position to win the ballgame. J.R. is still a big piece to the puzzle. I hope he’s learned his lesson.’’

— Mark Hale contributed to this report

marc.berman@nypost.com