The Chicago Bulls had the difficult task of taking on the best team in the NBA on Saturday night as they hosted the Boston Celtics. The Bulls made things tough on the Celtics and held around for the entire game, but Boston pulled away late to leave Chicago with a 124-113 win.

Playing the Celtics has been difficult for every team this season, and that is why they have the best record in the NBA. For the Bulls, it was more difficult because of issues on defense. Head coach Billy Donovan spoke to the media after the game, and he revealed the two things that are hurting the team most right now.

“The two things that stand out, and it's been a little bit better since the All-Star break, the two things that have hurt have been the rebounding and also the fouling,” Billy Donovan said. “Those would be the two things that have stood out that have kind of driven it (defensive rating) down. Our first shot defense has not been bad, it's been pretty good, but it's been the second chance opportunities that have hurt us. And then also, I think some of the fouling, the ability to go vertical, not trying to reach, some of those things. …If you're looking at last year compared to this year, that would be two areas that have probably hurt our rating.”

What changed for the Bulls since last season?

Chicago Bulls guard Coby White (0) defends Boston Celtics center Luke Kornet (40) during the second half at United Center.
© David Banks-USA TODAY Sports

Donovan made the comparison to last year, and while the roster is pretty similar, the lineups have changed a bit. Chicago has faced a lot of injuries this season and they have often times had to play with a smaller lineup. That can make things more challenging.

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“Clearly we're playing with a smaller group so collectively we've gotta rebound,” Donovan said. “It is what it is, there's times we get our guards down inside and they're trying, but there's times they're overmatched, and then there's times where we flat out just have to do a better job. I think another part of it is the discipline of the fouling. …Like I said, our first shot defense has been pretty good, but the fouling and the rebounding have got to be areas that we continue to try to shore up as best we can.”

There have been a lot of adjustments that the Bulls have had to make this season. If they are going to find success in the postseason, those adjustments will need to continue, and they will need to improve in the areas that Donovan mentioned.