Summary
Green had his best season of his career in '21-'22, getting legitimate rotation minutes for the Bulls. He has actually been a consistently efficient player throughout his career, and his 59.8% eFG% in '21-'22 was in the top fourth percentile for his position, according to Cleaning the Glass. That was highlighted by him converting at a very good 69% rate at the rim while also shooting an above-average 36% from three, numbers that mostly stayed the same or slightly improved over the last couple seasons, on a small sample size. He surprisingly didn't make a roster to start the '23-'24 season, and didn't re-sign with Chicago until late in the '23-'24 season.

Green isn't someone that creates off-the dribble (100% of his made threes throughout his career have been assisted), but he doesn't need to in order to stay on the court. He also gets a lot of offensive rebounds and has lowered his turnover rate. 

Defensively, Green is slightly undersized for a wing at 6'5", making it harder for him to defend some of the bigger NBA wings, but he works hard on that end and generally has been a positive contributor. He also can be disruptive, demonstrated by his good steal and block rates.

Like many role players, if Green can continue to hit threes at a solid rate, he could be a solid low-usage, high-efficiency role player. Green came into the league at an older age, as he will already be 31 when he hits free agency in 2024.
 
Cap Considerations
Green will be an unrestricted free agent with a $2 million cap hold and Non-Bird Rights. This means that the highest starting salary the Bulls could offer him using the Non-Bird Exception is $2.9 million. If that isn't enough, the Bulls could use their Mid-Level Exception to re-sign Green if he demands more than $2.9 million.

Other teams will have multiple ways to sign Green as even teams without cap space could use the Non-Taxpayer MLE, Room MLE, Taxpayer MLE, or Bi-Annual Exception to sign him. It's also likely that Green only gets minimum offers again, and he may not even get fully-guaranteed offers.