Kevin Garnett of the Celtics, right, battles Zydrunas Ilgauskas of the Cavaliers for a rebound Saturday night in Cleveland.

The Providence Journal / Kris Craig

CLEVELAND — The postgame “talk” after Saturday night’s ugly 24-point loss to the Cavaliers was actually a mere sentence out of the mouth of Celtics coach Doc Rivers.

“It was probably my quickest postgame speech of the year. I just said, ‘Let’s get it in.’ That was it,” Rivers said. “What speech do you need? Just look at the scoreboard. Sometimes you don’t have to talk.”

The quiet locker room emptied quickly. For a team that lost by double figures only three times all season, getting shellacked in a prime-time playoff game was a shock. Rivers insists on treating his players like professionals, and he knew the Celtics were embarrassed.

“Nothing needed to be said,” said Ray Allen. “Yeah, we should be angry, we should be mad at ourselves and disappointed, but it didn’t need to be said. We didn’t have to come in and be belligerent towards each other or scream at the top of our lungs. We’re all professionals and we know exactly what we did and what we didn’t do.”

The Celtics awoke yesterday and filed into a meeting room at the Ritz Carlton Hotel to begin preparations for tonight’s Game Four. All Rivers screened was a nightmarish first quarter, in which the Cavaliers shot 65 percent and the Celtics took a load of quick shots and fell behind by 19 points, 32-13.

“It was definitely worse looking at the tape. I didn’t even recognize the team or the guys out there,” said Paul Pierce.

Rivers didn’t enjoy it, either. “I told them that this was the toughest film session that I’ve watched this year. It was just out of character. Not that we would’ve won the game, but we’re better than that and they know it,” said Rivers.

The horrid effort was so surprising that it may be hard for the Celtics not to be second-guessing themselves right about now. The three road losses in the Atlanta series were explainable if only because the athletically superior Hawks fed off the energy of their home crowd and the Celts did have a chance to win each of those games in the final minute.

That was not the case Saturday. After holding LeBron James in check and watching his supporting cast offer little assistance in two wins in Boston, the Cavaliers appeared overmatched in the series. But a simple change of venue wiped that thought off anyone’s mind. Feeding off the energy of the 20,562 fans at the Quicken Loans Arena, the Cavs regrouped and blitzed the Celtics early on and cruised to the 108-84 win.

The Cavs are more than just James. Big man Zydrunas Ilgauskas (17.7 ppg. in the series) continues to bother the Celts and ex-Celtics Delonte West and Wally Szczerbiak showed they still have some pop in their shooting hands. James was held to 21 points, and the fact that the Cavs could win by 24 points with their star shooting 5-for-16 from the field must be a comforting thought.

The Celtics fell to 0-4 on the road in the playoffs. They finished 31-10 on the road in the regular season. Tonight’s Game Four at The Q is the critical swing game in a series that will either be headed back to Boston with the Celtics in command or have the look of a seven-game slugfest.

“We all need this win on the road,” said Pierce. “It’s like a Gorilla on our backs, trying to get a road win. I’m sure (my teammates) want it just as much as everybody in the state of Massachusetts wants this game. We’re going to play better basketball from here on out on the road, I can guarantee that.”

The key to even a chance at a win tonight lies on the defensive end of the floor. The Cavs shot 65 percent in the first half Saturday, with James content to pass (8 assists) and find teammates who were due to make shots. The Celts let West, Szczerbiak and Joe Smith loose for open looks while worrying too much about James. Late Saturday, Garnett said the Celtics intend on making those players keep showing they can knock down open shots, but they can’t cheat too much off of James, either.

“At times, Paul had LB straight up and we overhelped,” Garnett said. “In order for us to beat this team we have to make these other guys make some plays. I don’t think these other guys are used to making plays. Throughout the year LeBron has pretty much set these guys up to be successful.”

Ticking off the good performances of the other Cavs, Garnett said, “That’s not really this team’s character. LeBron makes so many different plays and affects the game in so many ways that these guys spot up and can hit threes. Tonight these guys made plays. They were effective, they were aggressive and they never looked back.”

The Celtics need to hold the supporting cast in check while James continues to struggle, shooting 22 percent in the series. That combination would add up to a road win that’s proving to be ever elusive in this playoff run.

kmcnamar@projo.com