December 15th is the date every NBA team has circled on its calendar, as that is the date that virtually every player in the league becomes available in a trade. Most, if not all, players who signed a free agent contract during the offseason can't be traded before December 15th.
The Memphis Grizzlies have four players who signed this summer as either their own free agents or from another team. The players they retained from free agency were Santi Aldama and Cam Spencer, and the players they signed from other teams were Ty Jerome and Jock Landale.
Santi Aldama, Jock Landale, and Cam Spencer have all played key roles as each of them is averaging at least 21.