Rick Carlisle lamented an "ugly" performance from the Indiana Pacers after his team lost to the Los Angeles Clippers.

The Pacers went down 151-127 to the Clippers on Monday, suffering a fourth straight defeat.

Since losing to the Los Angeles Lakers in the final of the NBA's in-season tournament, Indiana have won just one game, with that victory coming against the struggling Detroit Pistons.

And Carlisle pointed to a mentality shift being required if the Pacers are to turn things around.

"Tonight was ugly. It's just something that's not acceptable," he said after the Clippers game.

"I don't care how talented they are, or anything else, we just allowed them to really do whatever they wanted to do. I've got to take responsibility for not having these guys ready to play.

"We've got a huge target on our back because of winning some games in the tournament. The Pacers aren't sneaking up on anybody.

"But our mindset, if it's shifted to just simply trying to outscore teams and away from any kind of emphasis defensively, that's got to stop. If it means massive lineup changes, then that's what will happen."

"We're missing some of our best defenders right now, that doesn't help. But it's not a valid excuse. We're making a lot of mistakes, and we just need to do it better and we need to do it harder."

Carlisle did, however, refuse to accept full responsibility for the slump, putting the onus on the Pacers' star players.

"Our best players have to understand and they have to believe that the little things are important," he added.

"That concentration and focus are extremely important. And so when the best players believe it, they preach it and it becomes gospel. It can't just be the coach."

Tyrese Haliburton, who managed just eight points, echoed Carlisle's sentiment, saying: "I think that we got to where we were by just playing harder than people. And we’re not doing that right now. So the switch has to flip here, pretty quick."

While the Pacers are on a skid, the Clippers are in fine form, having now won their last eight games. It is the team's longest winning streak since a 10-game run in the 2015-16 season.

Kawhi Leonard, Paul George and James Harden ran the Pacers ragged, with the latter scoring 18 of his game-leading 35 points in the fourth quarter.

"It was fun to watch," Leonard, who had 28 points, said of Harden's fourth-quarter charge.

"We're not trying to play the score. We're trying to win the quarters. And even if we have 20 points, we've still got to do our jobs and be efficient."

Harden, who also added nine assists, said: "We're playing very, very well right now, so we just have to stay consistent in what we do. Every game is a new challenge for us as a unit.

"We're figuring it out, we're coming together, our chemistry is building game by game. There's a long way to go but we're definitely headed in the right direction."