Oklahoma City Thunder
There are not a lot of free agents from the Oklahoma City Thunder to pick from, but the one that stands out the most is Gordon Hayward, who had a miserable run with the Oklahoma City Thunder. For whatever reason, they never really integrated him into their team and essentially just had him be a catch-and-shoot guy, to who they never passed the ball to. He's far from washed, we saw what he could do Charlotte with the Hornets, so we know this isn't an issue with talent.
Hayward can still go, as he shot 47% from the floor and 36% from three while with the Hornets. They cut his minutes in half, going from 31 minutes a night to just 17, and then reduced the amount of shots he could take. Still, he shot well over 50% from three in Oklahoma City despite the decreased workload.
Another name to keep an eye on is Bismack Biyombo. He's not a starter by any means but for a handful of bucks, you could get a good defensive bench player. We're talking 15+ minutes per night and only in situations where you need a little extra help defensively.