College teammates Jimmy Butler and Jae Crowder made plans to go to dinner after Thursday’s game in Chicago but for a few short moments they weren’t just competitors but unexpected combatants, getting tangled up in the second quarter.

There looked to be some harsh words exchanged after Butler took a charge on an unsuspecting Crowder near three-quarter court, with Crowder putting the basketball in Butler’s chest while Butler was still on the floor, causing players on both teams to convene for some tense moments.

Celtics guard Isaiah Thomas got involved and then before Butler could blink, Bulls guard Rajon Rondo joined the proceedings, as pushing and shoving ensued before technical fouls were assessed to both teams after an officials’ review.

If one wondered whether these Bulls—a team that touts itself as young with so many players having three years or less professional experience—could play with some bark and bite, perhaps the season opener provided a bit of a positive preview for the next 81 games.

Nearby, an unbothered Dwyane Wade took a practice 3-point shot, much to the delight of the United Center crowd, as observers witnessed the first sign of tangible proof the Bulls have intentions on regaining a bit of an edge on the floor.

Wade joked and took it as a sign of respect between the two teams.

“It looked like it, right? Yeah. It was a little something out there,” said Wade when asked if there was some chippy play. “Every time we play them it’s gonna be like that. Two teams finding their way in the Eastern Conference. We know we gotta see each other a lot. They never give up. They can be down 30 with 15 seconds left and they’re still gonna fight.”

The Bulls have externally preached toughness from the start of camp. Although Wade didn’t participate in that meeting of the minds, he isn’t exactly running away from such matters.

And Rajon Rondo is competitively ornery enough to have his voice hard no matter the setting.

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“It’s been a big theme of practice,” Bulls coach Fred Hoiberg said. “We want to play with physicality and toughness. I think it was evident on the glass tonight.”

Yes, the Bulls outrebounded the Celtics by 19, but that could’ve been a by-product of the Bulls’ crashing the offensive glass on a porous shooting night. And yes, the slightly tense moment between Butler and Crowder probably won’t be an expected occurrence.

But when’s the last time one had multiple examples to dissect to discern this team’s level of toughness—or lack thereof.

“That’s something to show that the guys are out there fighting for each other,” Hoiberg said. “That they were playing with an edge. It happens with this game. You have to be competitive.”

Competition boiled over slightly, but considering the NBA isn’t exactly UFC, one doesn’t have to do much to display a little physical resolve.

“The fact that nothing escalated was good,” Hoiberg said. “The fact that those guys are out there and playing for each other and have each other’s back, that’s a huge thing right now.”

Too many times last season, it seemed the Bulls would submit in situations like those. Not that they were particularly soft, but it didn’t appear they had the collective will to fight for one another if an altercation arose.

Half the time, they looked like they could barely stand to be in the room with each other.

“It’s people’s will to win. Not saying a bad thing about anybody from last year,” Butler said. “To tell you the truth, I study the game and put in a lot of work but Rondo studies the game a lot. Every time I’m in the gym, he’s in the gym. That lets me know, these (dudes) are going to war with you. Every day. When I hit that deck, Rondo was right there. I wanna play with guys that’s gonna play hard, that’s gonna fight.”

And it didn’t take long for Butler to realize he has at least a couple teammates willing to jump in the foxhole with him.