Before Tom Thibodeau came along in 2010-11, the Chicago Bulls were just one of those Eastern Conference teams fighting for the No. 8 seed in the playoffs, but things are much different now.

When Derrick Rose has been healthy, the Bulls have been considered title contenders. Even when he’s not, they’ve overcome his absence and proved that their worth isn’t defined by Rose, although he is an important part of it.

Chicago remains a title contender this season, and having Rose back in the lineup is a large reason for that. But the addition of Pau Gasol and the growth of Joakim Noah and Taj Gibson have helped that case. Unexpectedly, though, Jimmy Butler is making a strong case for Most Improved Player, leading the Bulls with 21.7 points per game.

Combine all of that with Thibodeau as head coach, consistent veterans Mike Dunleavy and Kirk Hinrich and the emergence of Nikola Mirotic, and it’s no wonder fans and pundits alike have high hopes for Chicago.

The Bulls are 12-8 about a quarter-way through the season, and sport a 10-3 road record. But underneath that promising record and the roster’s potential lingers some concern.

For one, Chicago hasn’t looked like the defensively dominant team it has come to be. Granted, this year’s roster isn’t the same as those in the past, but the core remains the same.

Last season, the Bulls were the best defensive team in the league, giving up 91.8 points per game, the least in the regular season in the NBA. Currently, they’re ranked No. 20, giving up 100.5 points per game. That might be acceptable if they were a high-scoring team, but they only average 102.6 points per game.

After watching the Bulls struggle to score for the past few seasons, it’s nice to finally see the Bulls achieve offensive success. But that might as well mean nothing when their defense struggles. They aren’t a team that can mask defensive struggles with offensive efficiency enough to continuously succeed, and I’d much rather see them thrive on the defensive end and struggle to score than see them give up more points than they can rack up.

The Bulls have the ability to be the defensive powerhouse they once were, and they’ve proved that on the road. They just need to maintain that mentality regardless of the location.

It’s still early in the season, though, so there’s plenty of time for them to get back to their defensive identity — it shouldn’t be a difficult task. There just might not be much time until Butler’s excessive minutes get the best of him.

Butler has played in 18 of the Bulls’ 20 games so far, and he leads the league in total minutes (719) and minutes per game (39.9). With Butler’s reliable defense and improved scoring ability, it’s no wonder Thibodeau has decided to rely on Butler in the way he had previously relied on Luol Deng. But that’s just the recipe for injury, exactly what Chicago needs to avoid.

This isn’t to say Butler shouldn’t be playing a lot of minutes. He should, considering he’s the Bulls’ best two-way player at the moment. Butler just needs a little more rest, even just five minutes. It would lower the risk of injury and prevent him from becoming worn out before the playoffs arrive, just like how having Rose sit out games now will make him available when the games mean more.

There are other things to be concerned about when it comes to the Bulls, but their defense and Butler’s minutes need to be addressed now before it’s too late. Chicago has the potential to succeed; it’s just a matter of how that potential is utilized that will determine the extent of the success.

Ashley is a sophomore in Media. She can be reached at [email protected] and on Twitter @wijangco12.