All players that were cut yesterday clear waivers at noon ET this afternoon. That means teams can immediately start signing players to their practice squads. Each team can have up to 8 players on their practice squad.
Eligibility for the practice squad is limited to players who do not have an accrued season in the NFL, or were on an active list (53-man roster) for fewer than nine games during their only accrued seasons. Players that have served two seasons on a practice squad are eligible for a third season only if the team has at least 53 players on its active/inactive list for the duration of that player's employment.
Practice squad players are free to negotiate contracts to join other team's active list (53-man roster) at any time. One exception to this is that practice squad players may not sign a contract with his team's next opponent after 4pm ET six days preceding the game. That deadline is pushed back to ten days during bye weeks.
If a team sign's a player off of another team's practice squad, they are on the hook for at least 3 weeks active roster salary for that player- even if the player is cut before the 3 weeks is up.