18.17 For all matches from the start 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
1 February 2011 (24.00 CET) at the latest. This deadline cannot be
extended.
18.18 One player from the above quota of three who has played UEFA club
competition matches for another competing club in the current season may
exceptionally be registered, provided that the player has not been fielded:
− in the same competition for another club; or
− for another club that is currently in the same competition.
Furthermore, if the player’s new club is playing in the UEFA Europa League,
his former club must not have played in the UEFA Europa League at any
point in the current season.