By Cody Westerlund–

CHICAGO (670 The Score) — With a great deal of swagger backed by an unblemished personal record this season on his resume, Bulls forward Nikola Mirotic confidently made a proclamation after his team’s 108-85 throttling of the East-leading Celtics at the United Center on Monday night.

“The only thing I can say is Niko is back,” he said in an on-court interview.

Whether that comment was meant to be taken literally or figuratively or both, it wasn’t exactly clear. What’s certain is that after missing the first 23 games of the season with facial fractures and a concussion suffered in a practice fight with teammate Bobby Portis on Oct. 17, Mirotic is in great spirits and the Bulls are 3-0 when he plays.

Monday evening marked his finest game in his short season and one of the best of his four-year NBA career. Starting for the first time with rookie big man Lauri Markkanen sidelined with back soreness, Mirotic scored a game-high 24 points on 10-of-15 shooting and added eight rebounds. He hit a trio of 3-pointers, scored with strong moves on the low block, was active defensively and was the best player on the floor on a night that also saw Celtics star Kyrie Irving sit out with an injury.

“It seems like March, but it’s not,” Mirotic joked.

That was a reference to Mirotic’s penchant for shining in the month of March, a trend that started during his rookie season and one that has also left so many dumbfounded as to how Mirotic could flash so much potential at times and maddeningly disappear during other prolonged stretches.

Overcoming those inconsistencies was Mirotic’s goal in the offseason, over which he added 20 pounds of muscle and re-signed with the Bulls just prior to the start of training camp. And through the tough times of watching so many early season Bulls games at home with family and not with teammates, it’s what Mirotic kept in mind.

“I’ve been having great confidence in myself so far,” Mirotic said. “I’ve been watching a lot of film, and I put in a lot of work this summer. It’s just about the timing of when I’d be back, get more minutes and get my conditioning and strength back. Right now, I’ve been trying to be very aggressive there and just trying to make the right play.”

Mirotic is averaging 16.3 points on 54.8 percent shooting in his first three games back, and he credited his better shot selection and greater comfort in the post and in attacking the rim for his strong start. Coached Fred Hoiberg called his play “awesome.”

“He’s making plays for us on both ends of the floor,” Hoiberg said.

Until the Mirotic-Portis incident, the start of this rebuilding path for the Bulls (6-20) was expected to be rather mundane. An undermanned team would struggle until Zach LaVine returned from his ACL rehab, after which he’d be the focus and then the attention would turn to whether deals were made ahead of the trade deadline.

Portis’ punch changed the tenor. Beyond the losses coming rapidly in a 3-20 start, there were some doubts as to whether Mirotic would ever appear in another game for the Bulls. Behind the scenes, he and his camp made it known to the Bulls he didn’t want to share a locker room with Portis.

Mirotic hasn’t publicly expanded on that, other than to say if he’s here with the Bulls, it’s because he wants to be. He understands that means taking the floor with Portis, usually on the second unit when Markkanen is healthy.

They were a tandem that shined Monday, as Portis added a career-high 23 points.

“My only goal was to get back and try to help the team win,” Mirotic said. “And I think so far, we are having great chemistry — the team together and Bobby and I are playing good. I think we are finding each other during the game, and we are bringing that energy the team needs.”

As for the Mirotic-Portis relationship, it has remained professional in the workplace and non-existent outside those walls. With basketball back in his life, Mirotic is content with that and the understanding that a trade could be on the horizon after he’s eligible to be dealt post-Jan. 15.

“We’re just trying to make it simple, do our job,” Mirotic said. “I’m doing my job, and he’s doing his job right now. When we’re both on the court, it seems the team is playing well.”

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