By Cody Westerlund–

CHICAGO (CBS) — About two hours before tip-off of Wednesday evening’s exhibition contest between the Bulls and Pistons, rookie Chicago coach Fred Hoiberg admitted that the primary focus for him and his staff has been installing a new offensive system predicated on pace and space that then follows with an array of nuances.

This, he pointed out, may have contributed to the Bulls’ “inconsistent” play on the defensive end in the early going. So the hope Wednesday was the return of Bulls big men Joakim Noah (left knee) and Taj Gibson (left ankle) might be a start toward sealing the cracks of a leaky defense, given their experience, strengths and reputations.

In a 114-91 loss to the Pistons, they weren’t. No one was, really, as Detroit scorched the nets for 54.4 percent shooting. And now two-plus weeks into training camp and two nights after his team allowed 123 points to the Pelicans, Hoiberg made his feelings clear about Chicago’s defense.

“Disappointed,” Hoiberg said.

There’s no shortage of worries for the Bulls defense that Hoiberg and the United Center crowd witnessed Wednesday. He harped on an inability to get back in transition, which allowed the Pistons to score 24 easy fast-break points.

“We had guards that were supposed to get back that were crashing,” Hoiberg said. “We can’t do that.”

There was the lack of energy, as Hoiberg pointed out.

“It’s a pride thing,” Hoiberg said in a pregame interview, before Chicago allowed a middling offense to have its way. “If you get scored on, you got to take a stand. A lot of it is just individual – stay in front of the basketball. But you got to have that help there.”

The Bulls also weren’t immune to problems in the half court, which may prove to be their biggest challenge this year.

Hoiberg’s worry comes with the disclaimer that it’s only been five preseason games – including zero with the regulars all healthy and just one with all the big men ambulatory – but a few trends are emerging.

Foes are attacking Bulls second-year wing Doug McDermott, forcing him to navigate screens and make multiple efforts. While he’s proving to be a weapon offensively, McDermott’s often a step late defensively, either hung up in screens or giving too much space that in turn allows quality looks.

McDermott will have to work at it, for he’s in line for a significant role with Mike Dunleavy expected out until at least mid-December with a back injury. In one second-quarter stretch Wednesday, the Pistons ran several possessions in a row through rookie Stanley Johnson with McDermott guarding him. Opponents with more talented wings will surely do the same.

Through sheer force of discipline and a coach’s persistence in the Tom Thibodeau era of years past, the Bulls were adept at “icing” foes in the pick-and-roll – in other words, the on-ball defender worked hard to plant himself between the ball-handler and the screener, often forcing foes more toward the sidelines or corners.

It hasn’t looked quite the same under Hoiberg, who while not married to such a principle would like to keep the ball out of the middle of the floor, which sucks in the entire defense and forces it to defend the entire width of the court.

“Pick-and-roll defense, especially in the middle of the floor, we’re not keeping them on the side well enough,” Hoiberg said. “We need to get into our ice defense on the side. Things get into the middle too much. And we had too many blow-bys.”

It’s far too early to ring any alarm bells, and it’s worth noting that the Pistons’ biggest quarter Wednesday was the final one when the floor was littered with end-of-the-roster players. But the triple-digits that foes are hanging on the Bulls (at least 112 points allowed in three games already) has drawn their ire.

“We have to make a play call on defense and let the guard know what he needs to do,” Gibson said in reference to defending the pick-and-roll. “And we really have to get into the ball. It’s too easy right now. Like guys said, we have to challenge each other. You have to be mad at yourself for letting guys score on you.

“Our defense is lackadaisical right now.”

Cody Westerlund is a sports editor for CBSChicago.com and covers the Bulls. Follow him on Twitter @CodyWesterlund.