[yanked from the comments -yfbb]
According to Sam's mailbag, Deng was unable to play basketball a large part of the off season. This in addition to Derrick’s break from basketball and Noah’s groin might go even futher in explaining the slow start.
Sam: I’m not quite sure. Jo travels in the offseason, though the priority for him was to rest his foot. It’s why he upset some in his home country skipping joining the French team even as Tony Parker played. So he did the right thing for the Bulls. His foot seems fine. The only thing you’d have to say at this point was the preseason groin injury. What also doesn’t get brought up much is how little offseason work Deng was able to do still recovering from that spinal tap complication. Deng traveled a lot overseas as he does humanitarian work. But his illness was a lot more serious than he let on and he wasn’t able to work much in the summer.