Johnson agreed to terms with Corale Roanne on Saturday, Sportando.com reports.
Johnson was waived by the Grizzlies on Tuesday in order to make room for MarShon Brooks' 10-day contract.
Johnson was recalled from the G-League's Memphis Hustle on Wednesday.
Johnson provided 17 points (7-11 FG, 0-1 3Pt, 3-3 FT), 12 rebounds, three assists and two steals during Thursday's loss at Sioux Falls.
Johnson was traded to the Grizzlies on Thursday for James Ennis, Adrian Wojnarowski of ESPN reports.
Johnson, who was acquired from the Clippers on Monday, won't suit up in Tuesday's game against the Cavaliers, Rod Beard of The Detroit News reports.
Johnson has been traded to Detroit, along with Blake Griffin and Willie Reed in exchange for Tobias Harris, Avery Bradley, Boban Marjanovic and a first-round pick, Adrian Wojnarowski of ESPN reports.
Johnson was recalled from the G-League on Sunday, Elliott Teaford of Southern California News Group reports.
Johnson posted 11 points (4-10 FG, 1-4 3Pt, 2-2 FT), 10 rebounds, two assists, two steals and one block across 27 minutes in Friday's 111-104 preseason loss to the Lakers.
Johnson was recalled from the D-League on Monday, Brad Turner of the Los Angeles Times reports.