I don't believe he will be a back-up for any team anymore. He wanted to leave the Warriors because he wanted playing time he desired. These two years in NBA were by far the worst tenure of his career. He's still one of the top European guards(maybe still best), he showed that in the recent EuroBasket, so in Europe he can play for any team with a lucrative contract.
He'll very likely sign for Greek team Panathinaikos. I'll keep you updated.