He can only sign in the NBA this season if he gets bought out or waived from his Russian contract.
He can't be signed-and-traded.
He does have a cap hold.
Even if he were to become a free agent this season, we couldn't really afford to offer him more than a vet minimum contract, because we're right up against the luxury tax "apron" hard cap.
Just to add: He signed a new contract this summer for two years (plus a team option for a third year) with no buyout clause. He will probably never return to the NBA.