WALTHAM — Theirs has always been a rough-and-tumble friendship.

When Jae Crowder sees Jimmy Butler again tonight, Celtics and Bulls fans will do an immediate rewind to the second quarter of last Thursday’s game in Chicago. The pair collided while chasing a rebound, and a prone Butler scissored his legs around Crowder, who in turn fell and pressed the ball down on his former college teammate’s chest.

Words followed and the animus spread. By the time officials broke up the growing scrum, four technical fouls had been whistled, as the peripheral antics of Isaiah Thomas and Rajon Rondo warranted the refs’ attention.

But really, big deal.

Crowder and Butler guarded each other during practice the one season they played together at Marquette. Crowder smiled as he pushed the ball down on Butler at the United Center, maybe at the familiarity of it all.

“A lot, exactly, but we knew how to handle it. We always worked it out,” Crowder said yesterday. “We were never on the same team in practice. We guarded each other. When you have two alpha dogs, they tend to go at it.”

That alpha relationship started during Crowder’s first Marquette practice.

Crowder’s arrival was preceded by a significant amount of hype. He wasn’t recruited coming out of Villa Rica High School in the Atlanta suburbs. He was a chunky high school point guard in the midst of a growth spurt, and as such spent a year at South Georgia Technical College before moving on, for a year, to Howard College. He led the Hawks to the national junior college title, was named national junior college player of the year, and finally appeared on the radar of Marquette coach Buzz Williams.

“When I first got to Marquette, we went to this thing we called boot camp,” Crowder said. “Three weeks of conditioning, and (Butler) was acclimated to everything, and I had just come in from junior college and didn’t know what to expect. He was leader of the team at the time, a senior, and I was coming off being junior college player of the year.”

Thus the conflict. Butler wanted his cocky new teammate to understand who called the shots. That national junior college award had Crowder in a particularly heady state.

“I was feeling myself a little bit,” he said.

Ask Crowder about the craziest moment between him and Butler, and this is where he goes.

“I can’t recall what I said — a lot of bleep, bleep, bleeps,” Crowder said, laughing. “That’s one thing our coach let us do. He let us handle it. We all knew we were in it for the same cause. I just didn’t know what to expect at that time, and he did. (Butler) put me in my place, basically, told me you’ve got to work here. You can’t be all talk. That was our first time getting into it. That’s all it was — two alpha males going at each other. I wouldn’t say there was a rivalry between us, but we had one-on-one battles. We really went at it, man.”

Butler’s message to Crowder, that hard work is the overriding rule, has dictated the path for both players and their rise through the NBA. Butler comes in tonight as a two-time NBA All-Star and an Olympic gold medalist. Crowder is one of the more rugged defenders in the league and an emerging scorer.

“One thing we did have in common was that we just worked. I took that from him,” Crowder said of Butler. “If you had success, or if you had two bad games, you just worked. I can’t say anything bad about him. He was a hard worker, a competitive guy. We have a friendship, and the other night it was just competitive. But that’s my brother — that’s my guy.”