Why are some players not qualified for the Champions League after the transfer?

Because UEFA stipulates that a player can only represent one team in Europe in a season, if a player participates in the Champions League at the beginning of the Champions League season, he can't represent the new club after moving to another team in the winter break. For example, AC Milan player Van Bommel represented Bayern Munich in the Champions League group match in September 2065438+00. But it was loaned to AC Milan during the winter break of 20 1 1. As he has already represented Bayern in the Champions League in the same season, he is not qualified to represent Milan in the Champions League. Not only the Champions League, but also the players who participated in the Europa League and moved to the team that participated in the Champions League cannot represent the new team, such as Cassano of AC Milan, 20 10. Cassano represented Sampdoria in the Europa League. He moved to Milan during the winter break of 2011,and was not eligible to participate in Milan's Champions League.