BRIGHTON — Not all was bad in the Bruins’ 5-1 preseason loss to the Red Wings on Wednesday night at TD Garden. Malcolm Subban delivered a relatively solid performance — despite allowing four goals on 34 shots in his two-period workload — in his first action since sustaining a throat injury last year in Providence, while Matt Grzeclyk set up an odd-man rush for the B’s only tally and Zach Senyshyn made a quick recovery from an emergency appendectomy to suit up for Boston’s second preseason tilt of the year.

Not all was good, either. The young defense had issues clearing the puck and left open lanes for Red Wings shooters all night long. Ryan Spooner had a rough night at the faceoff dot, going 3 of 15, and was called for a rare faceoff violation. The transition game wasn’t fast enough, and most of all, the Bruins were one step slower than their opposition.

Over the last 48 hours, those mistakes have been a point of emphasis for assistant coach Bruce Cassidy and the rest of the coaching staff as they get set for a pair of preseason road games this weekend against the Red Wings (tonight) and Flyers (tomorrow night).

“We focused for the most part from [the defensive end] out,” Cassidy said following Thursday’s training camp sessions at Warrior Ice Arena. “Guys get overloaded this time of year, there’s a lot of newness so we try to work from our own end out, how we’re defending in our end, getting pucks back and breaking them out was kind of the focus today.”

“We have to make quick decisions,” assessed assistant coach Joe Sacco after Wednesday’s loss. “You’ve got to be able to think and move out there, and I think that our young guys, you know, they saw that early that it wasn’t going to be an easy night. But you can learn from that game, and I think, like I said, I think it’s just something that our young guys can take and say okay, this is how this game’s played at this level.”

Of course, pre-season evaluations are mostly based on player development, regardless of status.

For younger players like Grzeclyk, Senyshyn, Jake DeBrusk, Danton Heinen, Brandon Carlo and countless others, it’s about showcasing their potential to coaches and management. Veterans like Jimmy Hayes will use these games as motivation for a bounce back season. Other circumstances like shaking off the rust and playing after or recovering from injury provide necessary reps before taking the next step. And then there’s the World Cup conundrum for David Backes, Tuukka Rask, Brad Marchand, Patrice Bergeron, Zdeno Chara and David Pastrnak who need the appropriate amount of rest from game action before donning the Spoked-B for the first time in 2016-17.

Are results relevant? Sure. But it’s obviously not the end, be all.

After Wednesday’s performance, the Bruins coaching staff will look for a little more consistency this weekend, beginning tonight in Detroit. Below is a screenshot of the roster that will be traveling to Joe Louis Arena.