The first Argentine fans are already arriving to the Spanish capital to watch the game, but some may have to head right back to their country.

The consequences of hosting the second leg of the Copa Libertadores final at Santiago Bernabeu stadium have begun, with fans not being allowed into Spain.

One of those fans that had a ticket, but will not be able to make it into the stadium is Maxi Mazzarro, who is considered one of the most dangerous Boca Juniors' fans out there.

Spanish authorities decided to send Mazzarro back to Argentina since he has a long list of brushes with the Argentine law, including an 18-month stay in prison for allegedly being involved in a murder.

Mazzarro was identified by Spain's customs authorities, who decided to hold him inside Barajas' international airport. Earlier today, the Spanish National Police determined to send Mazzarro back to his home country, in order to ensure that the game goes on as planned, without any influence from radical supporters.

One more radical Boca fan, Rafael Di Zeo, was allowed to make the trip to Spain by an Argentine court of law. Only time will tell if Spanish authorities proceed in a similar manner against one of the leaders of Boca's support group known as "La 12".