Cavs must win tonight in Game 6

INDEPENDENCE (AP) — It’s do or summertime for the Cleveland Cavaliers.

One more loss, and a second straight Eastern Conference title is history.

One more win, and it’s back to Boston for Game 7.

After squandering a 14-point lead at Boston in a hail of missed free throws and getting entangled by the Celtics’ spiderweb-like defense in Game 5, LeBron James and his teammates are down 3-2 and facing elimination from the NBA playoffs tonight at Quicken Loans Arena.

They’ll go into Game 6 short-handed.

Guard Daniel Gibson, one of the club’s best perimeter shooters and a star in last year’s postseason, separated his left shoulder going for a loose ball early in the fourth quarter of Game 5 and will need a minimum of one week to recover.

The Cavaliers may be done before he’s well.

“It’s something we didn’t want to happen,” James said following a light workout Thursday. “It’s kind of the tale of our season — a guy goes down in the heat of a playoff series. He’s very key to our team. It’s not good seeing a guy who is that key to your team in a suit.”

Gibson underwent an MRI on his shoulder after the club returned from Boston. He was not available for comment. As a few of his teammates got in some extra work, the second-year guard struggled to slip a T-shirt over his head before sitting on a courtside bench alongside James.

Gibson made two 3-pointers and scored 14 points in Cleveland’s win in Game 4. In last year’s Eastern Conference finals, he scored 31 points — 25 in the second half — as the Cavs put away the Detroit Pistons in Game 6 to advance to their first finals.

For them to force a Game 7 in Boston, the Cavaliers may need someone else to come off the bench and come through.

Cleveland coach Mike Brown said he hasn’t decided whether to play reserves Devin Brown or Damon Jones in Gibson’s spot. He may just give extended minutes to swingman Sasha Pavlovic, who played only 10 — his average for the series — in Game 5.

The Cavaliers spent most of Thursday reviewing film before practicing their free throws. They went only 28-of-41 (68 percent) from the line in Boston and missed 10 in the second half, but what bothered them most was a lack of intensity in the third quarter, when the Celtics outscored them 29-17.

Center Zydrunas Ilgauskas, who scored just six points on only five shots in Game 5, couldn’t explain Cleveland’s passivity after leading 43-29 with less than four minutes to go in the first half.

“We had them on their heels,” he said. “[In the second half] It just seemed like we really weren’t into it. We came out a half-step slow.”