Diego Forlan and Antonio Nocerino both played in the Europa League preliminary round, but only one can feature in the Champions League at San Siro.
Inter were stunned to discover today that Forlan cannot be used in the Champions League until January.
This is because he played in the Europa League third preliminary round with Atletico Madrid.
However, Milan signing Nocerino also played in the same round, but is available for European competition straight away.
The reason for the discrepancy is that Palermo were eliminated in the third round, whereas Atletico Madrid went through to the Europa League proper.
“As a rule, a player may not play in a UEFA club competition for more than one club in the course of the same season,” reads the UEFA rule book.
“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.”
The mistake Inter made was not reading the rules properly, as they didn't realise Atletico Madrid's qualification even without Forlan taking part in the final play-off round automatically cup-tied him.
To make matters worse, the Nerazzurri only realised this after they had handed in the UEFA list, so players like Luc Castaignos and Andrea Poli are left off while Forlan is included despite being ineligible.