Bulls guard Jimmy Butler experienced knee soreness this week and missed Wednesday night's preseason game against the Pistons in Chicago. But there was good news after an MRI. From the team's Twitter account: 

The bruise is painful, obviously, but at least there's no structural damage which would have forced him to miss significant time, and severely damaged the Bulls' offensive plans. Butler's one of the few Bulls who can actually hit a jumpshot, and they need that badly. He's also a premier defensive weapon, and provides a secondary elite defender beside Luol Deng

We'll keep you updated on how much of preseason he misses.