As of the round of 16, a club may register a maximum of three new eligible players for the remaining matches in the current competition. Such registration must be completed by 2 February 2022 (24.00CET) at the latest. This deadline cannot be extended.
Any or all of the players from the above quota of three may have been fielded for another club in the qualifying phase, play-offs or group stage of the UEFA Champions League, UEFA Europa League or UEFA Europa Conference League.
If the registration of such new players causes the number of players on List A to exceed 25, the club must remove the necessary number of currently registered players to reduce the squad to 25 players again. The quota of the "locally trained players" must be respected when registering new players. Newly registered players must wear set numbers.
If a club cannot count on the services of at least two goalkeepers registered on List A because of long-term injury or illness, the club concerned may temporarily replace the goalkeeper concerned and register a new goalkeeper at any time during the season and complete the official registration list A with a goalkeeper fit to be fielded. An injury or illness is considered long-term if it lasts at least 30 days as of the day the injury or illness occurred. In case the recovery of the goalkeeper occurs before this 30 day period, the player must remain out of the players List A until the end of such period. If the replaced goalkeeper was registered as a locally trained player, the new goalkeeper does not need to be a locally trained player. The club must provide UEFA with the necessary medical evidence in one of UEFA's official languages. UEFA may require further medical examination of the goalkeeper by an expert appointed by UEFA at the cost of the club. Once the injured or ill goalkeeper is fit to be fielded again he can resume his position in place of his nominated substitute. The return of the original goalkeeper must be announced to the UEFA administration 24 hours before the next match in which the original goalkeeper is due to play.