A lot can change in 24 hours. 

Friday, the Bulls picked up their most impressive win of the season, defeating the Thunder 114-112 at the United Center. The Thunder, now 16-8, sit near the top of the Western Conference playoff standings.

And then Saturday night happened.

The Celtics rolled into the United Center and handed the Bulls their worst loss in franchise history. Boston beat the Bulls 133-77, a scoring deficit of a mere 56 points.

“Disappointing, disappointing effort, disappointing outcome after I thought a really hard-fought two games at Indiana and at home last night," said Bulls head coach Jim Boylen. "I’m not discouraged, but I’m disappointed.

"We gotta care more about our effort on a nightly basis, we gotta care more about playing for each other and tonight I thought we didn’t do that."

Before Saturday, the Bulls' worst loss occurred on Nov. 8, 2001, when the Timberwolves picked up a 127-74 win. Fred Hoiberg was on that Bulls team in 2001, ironically.

That 2001 game saw head coach Tim Floyd substitute all five of his starters at once (h/t to K.C. Johnson). Ironically, Boylen did that Saturday night after the Bulls starters shot 0-of-8 to open the game.

The Bulls did not score their first points until the 5:42 mark of the first quarter, going down 17-0 before Jabari Parker hit two free throws. Robin Lopez made the Bulls' first field goal at the 5:06 mark of the quarter on the team's 12th shot of the night.

 

"Gotta give Boston credit, I thought they made shots," Boylen said. "They kind of punched us and we didn’t respond."

Boylen substituted all five starters in the first quarter and said that the team did not honor the game with their competitiveness, so he gave the reserves a chance.

“I wanted to give the other guys a chance to see if they could right the ship a little bit," he said. "I’ve been a part of teams that have done that before; don’t like the five guys out here, don’t like that combination, look at a new combination, take them all out, let them sit there and think about it.

"We didn’t honor the game very well with our effort and our competitiveness, so why not take them all out? We’re a team, so sub five guys and see what they can do."

"It is what it is,” Zach LaVine said. "We gotta do what he says.

Boston led 35-17 after the first quarter, 64-43 at halftime and 93-60 after the third quarter. They shot 53.8 percent from the field for the game compared to the Bulls' 38.3 percent, hitting 22 three-pointers compared to the Bulls' six.

The Celtics also out-rebounded the Bulls 54-37 for the game, beating Chicago to lose balls late in the fourth quarter despite the Bulls trailing by more than 50 points.

"We were just following them around, I thought we were a step slow on everything, mentally and physically," Boylen said. "Is it want to, is it effort, what is it? I don’t know what it is, but I just wasn’t going to stand for it."

Not only did Boylen pull all five starters in the first quarter, but he also did after the Celtics opened the third quarter on a 5-3 run. LaVine and the four other starters sat for the final 21 minutes of the game, and the Celtics outscored the Bulls 69-34 in the second half.

LaVine scored 11 points in 19 minutes on 4-of-6 shooting. He said that he was embarrassed, mentioning how it sucked watching the Celtics' lead continue to rise.

"I felt embarrassed. I wish I was out there competing," LaVine said. "It sucks man, sitting there watching the score go up and up. I know we’re competing out there, but it sucks. You know you can help."

LaVine said there is a fine line between sending a message and embarrassing the players.

"Yea, I think so. We put a lot of hard work into this. I get up, compete every day. I think regardless of whatever the score is, I want to go out there and compete, but obviously we didn’t get a chance to do that.

But when asked how the starters don't construe getting pulled out as Boylen embarrassing them, Boylen said the team's play was embarrassing.

"I think your play is embarrassing, me subbing them is saving them, maybe. Maybe we saved them," he said. "The pro player thing, this is basketball; this is about honoring the game and doing the right things.

 

"Embarrassment is not giving the effort in that Bulls uniform, so I put five guys in that I thought could put the effort in.

"They’re disappointed, they feel bad about it. We need some leadership to step up, we need some guys to take leadership roles on the team."

Click here to download the new MyTeams App by NBC Sports! Receive comprehensive coverage of your teams and stream the Bulls easily on your device.