CHICAGO – Whenever the Indiana Pacers really needed a defensive stop Friday night, they failed to get one. Somebody from the Chicago Bulls was going to score, whether it was Lauri Markkanen (career-high 32 points), or Nikola Mirotic (28 points) or someone else.

The Pacers are not a very good defensive team, and they are missing their best player, Victor Oladipo (knee). That is not a good combination. Losing three straight games for the first time since Nov. 7, the Pacers dropped a 119-107 decision at the United Center, wasting a 30-point performance by Pacers point guard Darren Collison, which equaled his season high. Lance Stephenson (18 points, nine rebounds) also turned in a solid performance, starting his second straight game in place of Oladipo.

Afterward, Pacers coach Nate McMillan lamented his team's performance on the defensive end.

"We just did not challenge their threes," said McMillan, after watching the Bulls make 18 of 39 shots beyond the three-point line. "They will shoot the ball two or three steps behind the three-point line.

"We've lost that sense of urgency," said McMillan. "We're giving up big quarters defensively. Teams are really coming out and just jumping on us. Right now, we're not defending well at all."

The Pacers (19-17) will try to avoid a four-game losing streak when they host the Minnesota Timberwolves on Sunday. The Pacers lost four straight games earlier this season, and they snapped that losing streak in Chicago. However, the Bulls (13-22) are playing much better basketball now, having won 10 of their last 12. The Pacers found out the hard way that Chicago has found its rhythm.

Here are three takeaways from the Pacers' defeat:

1. The importance of Oladipo becomes more obvious with each game he misses.

The Pacers' record is 0-3 without Oladipo. Imagine where the Pacers would be this season if Oladipo had missed more games. Not a pretty thought. Lance Stephenson started in place of Oladipo for the second straight game, and played well for the second straight game. But Oladipo's shoes are enormous to fill. He has been one of the best guards in the NBA this season, making an impact at both ends. Before the game, Pacers coach Nate McMillan said Oladipo was doubtful for Sunday's home game against Minnesota, and would be re-evaluated after New Year's Day. It sounded like the earliest Oladipo may return would be Jan. 3 at Milwaukee, but that did not sound etched in stone. Oladipo was sitting on the Pacers bench, looking forlorn, unable to help his teammates. Nobody had to tell him how much he was missed.

2. Collison stepped up big-time for the Pacers.

About an hour before tip-off, Collison was still on the floor shooting jumpers — the last Pacer to go into the locker room to prepare for the game. The extra work paid off. Collison was superb, giving the Pacers a much-needed offensive lift. Collison mixed things up offensively with jumpers and drives to the basket, and he also created for teammates. Expecting Collison to play like this offensively every night is expecting too much, and he's a pass-first, shoot-second point guard. However, Collison is a capable scorer when he wants to pick things up offensively. He scored 30 points earlier this season during a victory in Memphis, and without Oladipo, Collison knew the Pacers would need help offensively. Collison provided it. But unfortunately for the Pacers, it wasn't enough.

"Sometimes you can attack for either yourself or others," said Collison. "I didn't want to wait like I normally do when Vic is in the game with us."

3. The Bulls were almost unstoppable early against the Pacers' porous defense.

Chicago's 37-point first quarter set the tone for this game. The Bulls got the shots they wanted, when they wanted, and built an 18-point lead just before halftime. Give the Bulls credit for sharing the ball and finding the open man. But against the Pacers, that wasn't hard to do.

Remember, the Bulls were playing without starting point guard Kris Dunn (patella tendonitis), who was a late scratch. Dunn is the Bulls' main facilitator, and his absence should have been a break for the Pacers. It wasn't.

The Pacers did not apply pressure on the Bulls' ball-handlers. They were not denying passing lanes. They did not close out fast enough on Bulls sharpshooters like Markkanen and Mirotic They did not help each other on defense with enough urgency. When you are missing a player like Oladipo, it becomes even more important to play a solid defensive game. The Pacers did not. Without Oladipo, they were at a disadvantage getting into a shootout with the Bulls. Offensively, the Pacers played well enough to win. But defensively, they did not get the job done.

Follow IndyStar sports writer Clifton Brown on Twitter @CliftonGBrown.

Read more on the Pacers: