Priority Sports, which represents Black, confirmed the news in a tweet.
Black, 29, is 6-foot-9 and last played in the NBA in 2017-18, when he appeared in 51 games in his second stint with the Rockets. He spent three seasons with the Lakers before that.
Last year, he played for Russian club Zenit St. Petersburg, signing in January and parting ways in July. Black spent 2018-20 with Israeli power Maccabi Tel Aviv.
“Black’s signing will bring the Nuggets to 19 players for training camp if they complete a rumored deal with Giorgi Bezhanishvili,” noted Arthur Hill of Hoops Rumors. “Denver has 14 guaranteed contracts, so Black will be fighting for one open roster spot.”