Per team's press release.
Joseph, a 6’7 forward, averaged 25.5 points, 7.5 rebounds, 3.5 assists, 2.0 steals and 1.0 block in two games while on assignment. He made his NBA debut against the Milwaukee Bucks and recorded one rebound and one assist in three minutes of action on November 2.
Jeff Green's swollen knee probably has a lot to do with this move. Not to mention overall depth issues with Rondo out and Wilcox sick.