LOS ANGELES — The Lakers have had a reversal of excellence over the past couple of weeks.

They entered the season with the expectations of being a prolific offensive team. And for a month, they were that.

Through their first 15 games, the Lakers had a 118.3 offensive rating (points scored per 100 possessions) for the league’s fourth-best mark.

But their defense lagged, ranking 26th in the NBA in defensive rating (117.4) after the season’s first month.

The script has flipped.

In their previous 11 games entering Monday night’s home game against the Detroit Pistons, the Lakers ranked No. 8 in defensive rating (108.2), including No. 1 (99.2) in their previous five games.

“You have to do your job, and then you have to trust that the next guy is doing his job,” first-year Lakers head coach JJ Redick said about the team’s defensive improvements. “And whether it’s been our discipline, we’re trying to keep the ball out of the middle, calling out coverages, keeping the basketball in front of us, our shifts, positioning and presentation, our low man — it’s guys doing their job. And you can have a good team defense and give yourself a chance to win if you do that on a night-to-night basis.”

But the Lakers’ defensive surge has coincided with an offensive lull.

They are No. 29 in offensive rating (104.4) over the past four weeks.

Redick reiterated that his team isn’t taking enough 3-point shots.

The Lakers entered Monday ranked No. 27 in 3-point attempts per game (33.4), including 29th in the previous 13 games. They also shot a league-low 30.6% from behind the arc during that stretch.

“In some ways, we need to shoot more 3s and we need to make more 3s,” Redick said. “That doesn’t mean we come down and just, no pass, one dribble shot. We’ve got to generate the right ones and we’ve got to do it with the right process and we’ve showed the guys a bunch of clips over the last week or so of us doing that.

“Make or miss, we’ve got to live with the result and we’ve got to do more of that. We need launch. We do. And that doesn’t mean we’re not trying to get to the rim every single time, but it’s those two things. We want to live in the paint. We want to shoot 3s. We haven’t shot enough 3s.”