With the signing of Pendergraph, I'd say the Spurs will leave that last roster spot open to review the players from the summer league. If Thomas impresses, he could probably be signed. But I think the Spurs leave that spot open for a 'just in case' situation, somebody being released from another team, player buyouts, etc.
"I'm always amazed to hear of victims so badly mutilated that they have to be identified by their dental records. What I can't understand is, if they don't know who you are, how do they know who your dentist is?" - Paul Merton