The deal is worth $2.6 million and has $220,000 in guaranteed money, according to ESPN. The contract will become fully guaranteed if Johnson remains on the roster past Jan. 7.
Johnson, 38, last played in the NBA during the 2017-18 campaign. He was named the Most Valuable Player of the Big3, the professional 3-on-3 summer league, and led his team, the Triplets, to the league championship.
Johnson, a seven-time All-Star, has averaged 16 points, four rebounds and 3.9 assists per game across 17 seasons in the NBA. He has spent time with the Boston Celtics, Phoenix Suns, Atlanta Hawks, Brooklyn Nets, Miami Heat, Jazz and Rockets.