The main thing to remember is he's a 20-year old rookie big man. Like most rookies, even ones not coming off micro fracture surgery, he's going to be inconsistent. He'll look dominant for a couple games and then totally lost for the next couple. The transition from college to the pros is always challenging for big men. Unlike high school and college, you're not always the biggest, strongest guy on the court. Instead of going up against kids your own age that you can physically dominate, you're going up against grown men who are just as big, or bigger, than you - and that have several years of NBA experience.
Give the kid time and be patient. He's already had some excellent games and been a big factor in some key wins. He's also stunk it up at times. It happens. He will continue to learn, and he will continue to recover from his surgery. At the very least, he's already helped improve two of the teams biggest weaknesses from last season: rebounding and interior defense. The rest of his game will come with time. Give him that time and you'll be rewarded for many years to come.
BNM