Kemba Walker cannot be traded to a team aggregated with other players from his team because 19 days have not passed since he was traded for (Normally 2 months, but shorter due to condensed season). He can only be traded away to a team by himself and other non-player assets from his team (draft picks, cash considerations, etc). This restriction expires after Jul 07, 2021.

John Collins is currently listed as a cap hold for the Hawks this season. Cap holds represent "placeholders" for pending free agents, unsigned draft picks, offer sheets, etc. Cap holds will have no trade value. You may update his contract in order to provide trade value for a Sign & Trade.