Mashack is listed out for Sunday's game against the Bucks after being placed in concussion protocol.
Mashack was diagnosed with the concussion after exiting Friday's 128-96 loss to the Raptors due to what the Grizzlies initially labeled as neck soreness. Sunday's contest marks the first of a back-to-back set, so the rookie second-round pick could have a tough time clearing the protocol ahead of Monday's game against the Cavaliers.