Summary
Unfortunately with Ball, we have to start with the injuries. After missing the second half of the '21-'22 season, he missed the entire '22-'23 and '23-'24 seasons. His knee issues just don't seem to be going away, and his career might be in jeopardy.

When healthy, Ball can be a real high-IQ, two-way player that could play a significant role on a very good team. We saw that at the start of the '21-'22 season, when Ball was healthy and the Bulls were near the top of the Eastern Conference standings. While his inability to create shots for himself limits his ceiling as a primary ball-handler, he can be a really good secondary creator. He developed his spot-up ability enough to be a threat, and his passing is valuable when attacking closeouts after getting the ball with the defense already in a scramble mode. He finishes decently well at the rim, and while he doesn't have a midrange game, he at least knows not to take shots from there.

Defensively, Ball is big enough and smart enough to guard multiple positions, which is valuable and makes it easier to fit him next to different types of players. He can be disruptive on defense, posting really good block and steal rates for a guard, never finishing below the 73rd percentile in either category when healthy, according to Cleaning the Glass. He anticipates passes well and jumps passing lanes for steals. 

Barring some unexpected health turnaround, Ball will almost certainly opt in to his player option for '24-'25, and will try to have a healthy season going into free agency in 2025. If he ever gets back on the court, it will be interesting to see how his knee issues have affected his game going forward. 
 
Cap Considerations
Ball has a $21.4 million player option for '24-'25, and if he declines that option he will be an unrestricted free agent with a $30.7 million cap hold and full Bird Rights, meaning the Bulls will have no restrictions on re-signing him. Since the Bulls will most likely be operating over the cap, and because his cap hold is greater than his expected starting salary, his cap hold is not really relevant.

Since Ball's starting salary will most likely be above the $12.9 million Nontaxpayer Mid-Level Exception if he opts out due to what he would get by opting in, only teams with cap space will be able to sign him. If Ball and an above-the-cap team have mutual interest, a sign-and-trade could be worked out. However, all signs simply point to Ball opting in.