After the Paul George trade and Patrick Patterson signing OKC has basically no cap left to sign any one. But they can still improve roster via trade/salary dumps to sign free agents. Here are 3 ways to do that.
1. Salary dump to Brooklyn. If OKC could trade Kanter to Brooklyn for 2/3 young players on decent contracts it would open up a lot for OKC roster wise, and free agency wise. They have re-signed Roberson now it is time to go after a PG (MCW, Mack, Lawson) or go for a big man (Sullinger, Baynes, Hawes).
2. With Celtics shopping Bradley, Crowder and Smart OKC should try and obtain them via trade for young players on smaller contracts (Celtics salary dump for Gordon Hayward) all 3 players would fill a need for the Thunder, Bradley to me would be the best for Westbrook and Co.
3. OKC has many holes they need to fill depth wise, namely backup PG/starting SG and Jamal Crawford recently became a free agent. Yes I know he’s aging and yes I know he is going to be somewhat expensive. But, he could do big things for the Thunder. Could be the Starting SG and move the ball up the court off the bench at times with how he can distribute. We all know how Donovan loves staggering minutes (see 2015-16) and it would only make it that much easier on everyone. He would make the team even more versatile in lineups (starting SG/Backup “PG”) and his scoring is what has made him 3x sixth man of the year.