For fucks sake:
18.07 As a rule, a player may not play in a UEFA club competition (i.e. UEFA Champions League and UEFA Europa League, but not UEFA Super Cup) formore than one club in the course of the same season. Exceptionally, however, a player who has been fielded in the first, second or third qualifying round of the UEFA Champions League or UEFA Europa League is entitled to play in the UEFA Champions League or UEFA Europa League for another club as from the group stage, provided that his former club did not qualify for the group stage of either the UEFA Champions League or the UEFA Europa League; moreover, as from the start of the round of 16 (round of 32 for UEFA Europa League), a player can be registered in accordance with paragraphs 18.18 to 18.21 below. A substitute player who has not been fielded is entitled to play for another club competing in the UEFA Champions League or UEFA Europa League in the course of the same season, provided that he is registered with the UEFA administration in accordance with the present regulations.
And, if he is facing a ban and the club he is at has registered him for that competition, he is unable to be fielded and therefore takes the suspension at the said club. If he subsequently moves on, that club re-registers with the competition providers with his ban having been served.
Comprende?