I'm sure you don't rate him highly since he's offensively challenged and you probably don't watch this team on a game-to-game basis, but OKC just aren't the same without Andre Roberson, and yes I'm 100% serious. Yes, they did beat GSW the second time without him, and hell, might even beat them a third time this week (I sure hope so). But in general, their defense just isn't the same without him. In Roberson and George, they had by far the best combination of perimeter defenders in the league. The length, athleticism, and defensive awareness they provided was insane. It made them match-up great with teams like GSW and the Rockets. Plus, Roberson, like Adams (who you also didn't rate highly 2 years ago, which is nuts), is their defensive glue guy. It's not just what he does individually, but he's the guy communicating and leading their defense as a unit. They have a serious problem at the shooting guard position now as Ferguson is still a rookie and has played like shit, Abrines can't guard anyone (and they don't even get him shots down the other end which makes him useless) and Huestis, who in theory is the closest to Roberson, hasn't filled his shoes. The fact that they were inactive at the trade deadline was a big surprise as they haven't sorted out their problem at that position. By all metrics, OKC are actually the top defensive team in the league with Roberson on the floor, and outside the top 10 when he's off. That says everything right there.
Plus, Donovan had actually found a way to use Roberson effectively on offense. He no longer stands around the perimeter to completely kill their spacing since the defense just ignores him and he can't make a jumper to save his life. He turned into a slasher, cutter, screen setter and board crasher, thus allowing George and Melo to space the floor themselves. Their offense, ironically, is much better when he's on the floor.
The good news is there's enough time until the playoffs for them to figure things out without him. And if this notion seems laughable to anyone, check OKC's record with Roberson and check their record without him. They were actually undefeated with him in the lineup since December up until his injury (insane), and have lost 5 times since (to only 3 wins).