"This is all about opportunity," said Nelson, a co-owner of the Legends. "This is Delonte joining the league and getting back in front of NBA teams' eyes."
Dallas has been shuffling veteran guards on the roster most of the season. Derek Fisher signed in November before deciding three weeks later to return to his family in Los Angeles after injuring a knee.
Mike James is on his second 10-day contract, and the Mavericks must decide by Sunday night whether to guarantee his deal for the rest of the season.
West was a valuable role player alongside veteran guards Jason Kidd and Jason Terry last season, even starting 33 games as the backcourt struggled with injuries before he was sidelined by a broken finger. He was close to his career averages with the Mavericks, at 9.6 points and 3.2 assists.
Part of West's value a year ago came from being a younger, experienced player to help point guard Kidd and Terry. The Mavericks have a much younger backcourt in Darren Collison and O.J. Mayo.
West was suspended for the first 10 games of the 2010-11 season after pleading guilty to weapons charges in Maryland.