Best duo in the East is back at the UC on Monday, and Bulls are green with envy

It will be quite the treat for the crowd Monday at the United Center.

The fans will have the opportunity to plop down in a seat, grab some popcorn and watch the best duo in the Eastern Conference go to work.

Bulls stars DeMar DeRozan and Zach LaVine will get an eyeful, too, because it isn’t them. While DeRozan and LaVine can make an argument about being a top-five duo in the East, the Celtics’ Jayson Tatum and Jaylen Brown are No. 1.

It’s not really even close. Not only are they young and able to score, but they also excel defensively, a department in which DeRozan and LaVine fall far short by comparison.

That’s what makes the Celtics (3-0) a threat to play into June again. Not only are Tatum and Brown capable of lighting up an opposing defense for 30 points apiece on any given night, but they just as easily can lock down opposing scorers for 30-plus minutes. That’s why their star power shines brighter than anything the Bulls have.

The biggest concern coming out of the Bulls’ loss Saturday to the Cavaliers in their home opener is how they can get enough defense from DeRozan and LaVine to make sure the bleeding stops after back-to-back losses.

DeRozan is what he is at this point in his career. He’s not a lockdown one-on-one defender, but his team defense is above average and his IQ is a strength.

He displayed that late in the Bulls’ loss Friday against the Wizards by stepping in front of a pass by Bradley Beal with 33.1 seconds left and going in for an uncontested dunk. The play was more about anticipation than good defense, but it enabled the Bulls to tie the score.

The Bulls, however, have to get LaVine back to being a serviceable defender. That wasn’t a question at this time last year. LaVine was coming off Team USA’s run to an Olympic gold medal and had emerged as one of the better defenders on the squad.

That carried over when he put his Bulls jersey back on. Along with fellow guards Lonzo Ball and Alex Caruso, LaVine helped the Bulls become one of the more disruptive backcourts in the league early last season. His defense suffered, however, when his left knee started bothering him.

But that was supposed to be a distant memory after LaVine had a clean-up surgery on the knee during the offseason and claimed he felt 100%. The Bulls sure believed it, signing him to a max contract worth $215 million over five years.

Now it’s hard to figure out what to believe. LaVine’s knee issue has him back on a load-management schedule, and his defense is back to shaky at best.

Look no further than the third quarter against the Cavaliers, when coach Billy Donovan pulled LaVine earlier than usual in his rotation. He wouldn’t admit it was solely because of LaVine’s defense, but he didn’t deny it, either.

‘‘I think for our team — not just Zach, but collectively as a team — we all need to be better defensively,’’ Donovan said. ‘‘I would throw Zach in there with our team.

‘‘I took him out in the third because I left him in too long in the first. I just wanted to give him [time] off to try and recover.’’

Maybe, but the uncertainty about LaVine’s knee doesn’t bode well for finding a quick fix to the Bulls’ defensive issues.

On Monday, however, LaVine and DeRozan will get an opportunity to see how it’s done. Tatum and Brown will make sure of that.