Zola collected one of Chelsea's four yellow cards in an otherwise splendid 2-1 triumph over the Spaniards of Real Betis in Seville on Thursday night.
The result means Gianluca Vialli's team are on the doorstep of their sixth major semi-final in five years and can even go through with a 1- 0 defeat in the second leg against Betis at Stamford Bridge in two weeks.
But Zola's yellow card after a penalty-box challenge by Betis' Yugoslav defender Hristo Vidakovic sent him sprawling just before half-time last night means the pounds 4.5m striker will be automatically suspended for one match in Europe if he is booked again in the second leg.
Zola was upset about the decision by the Bulgarian referee, Atanas Ouzounov, a late replacement for Sweden's Leif Sundell who was taken off the match by Uefa last week after being spotted fraternising with Betis officials at a recent Spanish League match.
Zola said: "I do not dive. I have never played the game that way. The referee gave his opinion but how far away was he from the position? I was fouled and it should have been a penalty. Now, instead, I have a yellow card when I was the one who did nothing wrong."
But Zola will have to live with the booking as Chelsea's assistant manager, Gwyn Williams, explained: "There is no appeal mechanism against cautions in Europe. We can't do a thing about it. But it's all right because I'd bet Franco won't be booked again for another six months. We all know what type of player he is."