The 6-foot-8 Griffin was originally signed July 18 after playing for the Mavs in the Las Vegas Summer League, where he averaged 9.8 points, 2.8 rebounds, 2.0 blocks and 1.3 steals in 19.3 minutes. He saw action in two preseason games for Dallas.
Togashi, who is listed at 5-foot-7, was signed Oct. 15 and did not play in a game for the Mavs.
Both players are likely to play for the Texas Legends, the Mavs' D-League affiliate.
The Mavericks' roster now stands at 18 players.