Dwain Price of the Star-Telegram reports that the Mavs have signed Ruben Wolkowyski and Chris Robinson to one-year, nonguaranteed minimum-wage contracts Monday, bringing the number of players under contract to 18.  They have also hired Thomas Hill as the new Assistant Player Development Coach.  However, Dirk Nowitzki's signing -- a formality -- has been delayed as Nowitzki's waits for his agent to arrive from Europe.