His biggest need to improve is his defensive skills.
When the team loses possession in the front court, he needs to run like Alvarez and stay close to the defensive player holding the ball. Too often, he just stands in place, which is not enough.
The team's frontcourt players are generally around 170cm tall. Nunes is 183cm tall and is a big guy, so he can intercept a larger area. He needs to do more defensive work in the front court.
If he can defend well, his attack skills will be a bonus.
If he can't help the team defend, then it's obvious that his skills are not enough for him to stay in this team. He's not an academic player like Rico and Bobb.