This will definitely harm Memphis to play without him in the first 30% of the season, at least they don't have to pay him for that time I guess. 
On a side note, Memphis Grizzlies may be just fine even without Ja Morant overall. Honestly, they are now used to playing without him lol.
Without Ja Morant, the Memphis Grizzlies had a:
- 20W-5L record in the 2021-22 season
- 11W-10L record in the 2022-23 season
But regardless, it's not what I really like to point out but the suspension Morant received. What kind of sh*t is that. It's like the league is not considering that as a serious case. Superstar, All-Star level or even a role player, should have received a heavy penalty for such a case like that.