Derek Fisher is in advanced negotiations with the Oklahoma City Thunder to sign with the Western Conference leaders after clearing waivers, according to sources close to the situation. ESPN.com Sam Amick: Sources say the Kings will pick up Terrence Williams on a 10-day contract. He was cut by Houston this week. Twitter The Grizzlies and Gilbert Arenas have made it official: The free-agent guard will join the team for the rest of this season. Griz general manager Chris Wallace confirmed the deal today. Arenas, who was in Memphis