Bears tight end Trey Burton was held out of practice for a second consecutive day at Family Fest on Saturday night at Soldier Field — a precautionary measure with Burton recovering from offseason sports hernia surgery, coach Matt Nagy explained.

“I felt like we might have been putting too much on him right away, so I’m going to just make sure I’m being real cautious with him,” Nagy said. “I want him to feel real good and we just felt like the last couple days he’s been a little sluggish.”

Fair enough. But the Burton situation bears watching, if for no other reason than the vibe of this training camp has been so good, you keep waiting for something to kill the feel-good buzz of Camp Kumbaya.

This is the Bears we’re talking about. Drama and dysfunction have been part of their DNA even in the best of times. But training camp in Matt Nagy’s second season has gotten off to a noticeably serene start. “The Bears should be concerned about …” used to be the easiest entry in any of our state-of-the-Bears stories in the Sun-Times. In last week’s review of the first week of training camp, it was the toughest.

In fact, the concern that Mitch Trubisky and the offense haven’t shown discernible signs of the progress that was promised in the offseason is being trumped by the bright side — Khalil Mack and the defense look like they’re ready to pick up where they left off last season under Vic Fangio.

We’ll see if that ends up being a weak rationalization/excuse — that as it turns out, a stagnating offense actually made the defense look better than it was in training camp. But the defense has earned the respect after a magnificent improvement to elite status last season.

In fact, the Bears’ defense is a perfect illustration of just how well things are going this season. A year ago today the Bears’ starting linebackers in training camp were Sam Acho, Nick Kwiatkoski, Danny Trevathan and Leonard Floyd, with Isaiah Irving the third pass rusher. Today it’s Mack, Roquan Smith, Trevathan and Floyd — with Aaron Lynch the third pass rusher.

Smith’s virtual camp-long contract holdout last season was managed well by Nagy and the players, but still was a bit of drama the Bears haven’t had this year. And speaking of drama, Sunday was the fifth anniversary of a classic Bears training camp moment in 2014 — tight end Martellus Bennett body-slamming rookie cornerback Kyle Fuller after Fuller dared to strip the ball from Bennett on a pass play.

Coach Marc Trestman ended practice immediately after that incident and Bennett was suspended indefinitely — and ultimately for six days. A year earlier, in Trestman’s first season in 2013, Bennett slammed nickel back Kelvin Hayden to the ground in a training-camp practice, causing a bench-clearing brawl.

There’s always something in training camp. At Family Fest that season, Hayden suffered a season-ending torn hamstring. In 2016 at Family Fest, starting center Hroniss Grasu suffered a season-ending torn anterior cruciate ligament. Wide receivers Alshon Jeffery and Eddie Royal, tight end Zach Miller and Trevathan all were out with injuries — a harbinger of injury-shortened seasons for all of them.

And that Family Fest was also marked by guard Ted Larsen fighting linebacker Lamin Barrow — with Kyle Long bolting from his sideline conditioning for a calf strain to dive-bomb the sizable scrum on the field.

That was nothing compared to the 2015 battle between defensive tackle Jeremiah Ratliff and center Will Montgomery that was unsettling even by training-camp-fight standards — with several teammates unable to calm down the volatile Ratliff. It was a predictable prelude to Ratliff’s bizarre demise after clashing with team personnel, including general manager Ryan Pace.

Coach John Fox dismissed the training-camp incident, as most coaches do.

“I haven’t been in a camp where we didn’t have that, ever, in 26 years,” Fox said.

Though the Ratliff incident was an oddity, practice kerfuffles generally are a rite of NFL training camp. But this camp has been void of any kind of discord so far. Defensive end Akiem Hicks and center James Daniels appeared to have a disagreement in practice last week, but nothing materialized. If the defense continues to get the best of the offense, you have to think tempers will flare at some point. But for now, all systems are go for a team that is on a roll.

Two years after “Mike Glennon is our leader” never gained traction outside of the building, every offseason narrative is in play. Mack and Smith are benefitting from being in camp after not participating last season. The defense, in turn, looks to be making a seamless transition from Fangio to Chuck Pagano. David Montgomery already looks like a better fit for Nagy’s offense than Jordan Howard. Daniels and guard Cody Whitehair are comfortable playing their best positions.

And, for now anyway, the plan to develop a mentally tough (and salary cap-friendly) kicker through a pressure-packed derby is working — Eddy Pineiro (33-for-37, 89.2 percent) and Elliott Fry (34-for-40, 85.0) have yet to miss consecutive kicks.

The missing element is Trubisky and the offense. Nagy is confident both will be fine when the season opens on Sept. 5 against the Packers. The way things are going this camp, it’s hard to doubt him. If Trey Burton returns to practice this week, it’ll be another indication that Nagy still is on one hot roll.