Indiana’s defense has been lit up without Myles Turner. But his absence isn’t a catch-all, and therefore pressure shouldn’t be heaped on him to be a cure-all.

After leading the league in defensive rating (at 101.9 points per 100 possessions) through their first 34 games, the Pacers have ranked 26th in defensive efficiency (114.7) since. And five of their seven games in that stretch have come against bottom-10 offenses.

Outside of the master class in hustle they put on against Detroit, in which it appeared as though they needed a stop as much as their next breath, they’ve been forced to hold on for dear life (oh, hi, Cleveland storming back with 72 second-half points) or fight fire with fire (hey, almost didn’t see you there, Atlanta and Chicago).

That was fine against lowly opponents, not so much against Eastern Conference contenders.

All they saw was smoke against Toronto and Boston, surrendering 121 and then 135 while losing by an average margin of 21.5 points.

Here’s what’s been going on.

Myles Turner is out

Playing the fourth game of a five-game road trip on the second night of a back-to-back in Boston, the Pacers were a step slow disrupting passing lanes. They struggled to stay cognizant of cutters when Al Horford caught the ball with both feet in the lane. And they made straight-line drives look like leisurely afternoon strolls in the park.

As Nate McMillan described it, they looked “gassed.”

Exacerbating the sluggishness, however, was the conspicuous absence of the team’s safety net.

Despite entering the game as one of the lowest scoring teams in the paint, the Celtics racked up 56 paint points, repeatedly gaining chest-to-shoulder advantage without need of a screen and then finishing with ease without the repellent of Turner’s anti-gravity.

For all of his hyper-productive strengths, Sabonis just doesn’t have the closing speed and impeccable timing of the player he understudies.

“We know we’re better than that,” McMillan told reporters following the lopsided loss. “Of course, we’re missing the anchor of our defense but we’ve got to continue to work.”

Turner is leading the league in blocks and he’s defended the third-most shots per game within 6-feet of the basket. On high-volume, Indiana’s starting center has held opponents to a ridiculously stingy 53.4 percent on those shots, a mark nine percent worse than their average.

Notably, the Pacers didn’t record a single block against the Celtics for only the second time this season (the first being the night before in Cleveland), and the combination of tired legs mixed with altered lineups and perhaps more conservative perimeter defense translated into just three turnovers being forced by halftime.

So, Turner being out matters. It really, really matters, but so does the slippage that started before he broke his nose and so do some of the shortcuts that have been taken since.

Teams have been pulling out some of the cheat codes for how to score on the Pacers.

Without like-sized defenders capable of switching across multiple positions, Indiana’s drop coverage has revealed a tendency to get picked apart by double-drag screens.

Here, with Oladipo chasing DeAndre’ Bembry over the top of both screens and shooters dotting the strong side, the pressure is on Darren Collison, and Darren Collison alone, to bump Dewayne Dedmon on the roll and contest Jeremy Lin as the popper.

Because Turner has to backpedal with Bembry until Oladipo can recover, Collison gets pulled into the lane by Dedmon just long enough for Lin to line up his shot from three.

Or, how about when Lin took a shot to the thigh and Collison tried his dead-level best to hold Dedmon back, and the Hawks still managed to generate an open dunk.

This happened over and over and over again across both games with Atlanta — regardless of if Sabonis, Turner, or even Thad was defending the second screener.

Toronto got in on the fun, too.

This is a swing fist action, but the tail end of it functions like a double drag. As soon as Bojan Bogdanovic made the decision to stick with Danny Green, Thaddeus Young got left carrying the bag of deciding who to guard between Kyle Lowry and Pascal Siakam.

In the second half of the second game with the Hawks, the Pacers eventually countered by having Turner blitz Trae Young, a newfound luxury of the 22-year-old’s improved fluidity.

That being said, the Pacers were already scrambling here, there, and everywhere against the Raptors without the added complication of attempting to defend 4-on-3.

Guards screening for slashing bigs is another targeted area where teams have started to wreak havoc.

Particularly nightmarish was when the Raptors used Fred Van Vleet as the screener for Siakam, thereby putting Sabonis in the unnatural position to either have to fight over the top as the on-ball defender or regretfully concede an untenable mismatch, like so:

Switching Thad’s elastic defense onto guard-like fives is the simplest solution (why was Sabonis even matched up with Siakam in transition when Ibaka was on the floor?); however, the downside of putting Sabonis or Turner on the opposing team’s weakest three-point threat is that doing so will pull the team’s best rebounder and/or defensive anchor away from the rim while coming pre-packaged with risk against speedier fours.

Cutting corners hasn’t helped

The simple act of Alec Burks checking into the game shouldn’t have opened the door for Collin Sexton to walk unabated into a three.

On prior possessions, Bogdanovic had been matched up with Sexton so that Victor Oladipo and Cory Joseph could attempt to cool down Cameron Payne and Jordan Clarkson. When Burks subbed in for Payne, Bogdanovic took his number as the inbound passer with Oladipo denying Cleveland’s rookie point guard.

And yet, on the next trip down the floor, Indiana’s two top scorers had no idea who was supposed to be guarding who.

Similar errors contributed to Toronto’s 3-point shooting barrage. Dribble penetration was a problem made worse by things like Sabonis throwing away an inbounds pass, Thaddeus Young bobbling a defensive rebound, and Oladipo tripping and falling.

They lost track of shooters in transition. They let long rebounds bounce on the ground. They didn’t stunt when their bigs were in a deep drop. And they settled for shooting the gap against a team that was red hot.

In that regard, they have to start making their own luck until teams stop hitting all of the shots

Toronto shot 17-of-33 from three on Sunday compared to 7-of-30 in December. They also found the bottom of the net on a higher percentage of wide open threes (64 percent up from 40 percent) on near to the same volume (15 up from 14).

In Chicago, Kris Dunn made two threes in the final six minutes of the fourth quarter after having only made five the whole season. Likewise, Cameron Payne (yes, the same Cameron Payne playing for his NBA-life on a 10-day contract) came off the bench and scored 8 points for the Cavs in the first four minutes of the final frame, draining two threes and drilling a floater.

It’s been much more a make, than a miss league.

But, that has a tendency to happen when teams are allowed to get comfortable.

The Pacers are a better defensive team than they’ve been the last seven games, and that will likely prove out once they get some rest and Myles Turner gets healthy.

To defend at the level they were through the first 34 games against the depth and versatility of the Torontos and the Bostons; however, they have some cleaning up and figuring out to do — even then.