Desailly lashed out at the Spanish striker early in the second half of Chelsea's 3-1 defeat, an incident missed by match referee Urs Meier but subsequently studied on video by the UEFA Control and Disciplinary Body who imposed the suspension for his "violent conduct".
The French international will therefore miss the second leg against Monaco on 5 May as well as the final should Chelsea advance. Desailly and his club have until midnight on Monday 26 April to appeal against his ban.
Monaco midfield player Akis Zikos will also miss the second leg through suspension after the Control and Disciplinary Body confirmed his red card in the first leg. The Greek international was dismissed after raising a hand at Chelsea midfield player Claude Makelele.
In a statement, UEFA conceded that Makelele's reaction - a theatrical tumble - had been "unsporting". It said: "The Body also noted the unsporting behaviour and provocative attitude of the Chelsea FC player Makelele, who dived and feigned injury after the incident."
Jorge Andrade dismissal stands
RC Deportivo La Coruña have also lost a player for their semi-final second leg against FC Porto after the Control and Disciplinary Body rejected their protest against Jorge Andrade's red card in Wednesday's first-leg tie. Deportivo's Portuguese defender was sent off in the closing minutes of the 0-0 draw after aiming a kick at Porto playmaker Deco. Deportivo can appeal against the decision if they wish.
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