Nope. Don't overreact based on a handful of regular season games. Make San Antonio prove they can remain healthy for the playoffs and actually beat OKC.
This summer makes a lot more sense for them to make a move like that. Believe it or not, SGA and Hartenstein are the only two players on the roster that make more than $20 million this season. So you would have to move 2-4 players to get a star in. Plus, teams will want that LAC pick. Wait till the summer, you see where that pick ends up. If its outside the top 3 then trade it. Chet will be making $41 million then, so him + a pick or two should get the job done without ripping apart their roster.