What limits the transition of a player from the PUP list to active roster?

The transition of a player from the Physically Unable to Perform (PUP) list to the active roster is limited by a specific timeframe, which is set at 21 days. Once a player is activated from the PUP list, they must either be placed on the active roster or remain on the PUP list for the entire season. The 21-day window allows teams to evaluate the player's recovery and readiness for game participation.

This timeframe is crucial for teams, as it provides a structured approach to managing players recovering from injuries while ensuring decisions are made timely concerning roster spots and game strategy. If a player hasn't shown sufficient progress to make the active roster after the 21-day period, they will remain on the PUP list, thus impacting their availability for the rest of the season.