Johnson in line to replace Nelson

With a nudge from NBA headquarters in New York, Avery Johnson of the Dallas Mavericks is retiring as a player to focus on his new role as Don Nelson's lead assistant, league sources told ESPN.com.

Donnie Nelson, meanwhile, is leaving the Mavericks' bench to focus on his role as the team's president of basketball operations. The younger Nelson has been serving as an assistant coach and as Dallas' personnel chief since the summer of 2002, when he was promoted after interviewing for the Denver Nuggets' head-coaching opening.

Sources told ESPN.com that the Mavericks were somewhat forced into these changes by the league office, because of the NBA's apparent contractual objections over Dallas' plans to keep Johnson on its active roster as a player-coach. Since the advent of the salary cap for the 1983-84 season, the league has forbidden teams from employing the player-coach concept.

Johnson, though, has said repeatedly that he had no intention of playing this season unless an emergency demanded it. Joining Del Harris at the forefront of Nelson's staff brings Johnson one step closer to succeeding the elder Nelson as the Mavericks' next coach, a move widely seen as inevitable. Nelson, who turned 64 in May, has one season left on his contract after this one.

The younger Nelson has been angling to spend more time in his front-office role anyway, which seems even more sensible now that Johnson is by far the in-house favorite to be the next head coach. Since his promotion, Donnie Nelson has established himself as Cuban's right-hand man when it comes to roster assembly, with Don Nelson third on the ladder for decision-making.

Johnson played for six teams in his 16 years in the NBA, averaging 8.4 points and 5.5 assists per game and helping San Antonio win its first championship in 1999.