In 2000, Blackman was tapped to be the defensive coordinator for the Mavericks under coach Don Nelson. The next year, he served as an assistant coach for the German National team and helped lead them to a bronze medal at the 2002 World Basketball Championships in Indianapolis. During the 2004–05 season, Blackman was hired as one of the Mavericks television analysts, along with Matt Pinto and Bob Ortegel. For the 2005–06 season, Blackman returned to the Mavericks' bench, serving his first season as a full-fledged assistant coach. In July 2006 he was promoted to the position of Director of Player Development.