Porto president Pinto da Costa confirmed they rejected an invitation to join a breakaway European Super League as they "cannot participate in anything that is against the principles and rules of the EU and UEFA,'' Sky News reports.
Reports last night claimed Porto could be one of the additional three Founding Clubs which are yet to be announced.
"There were informal contacts from some clubs, but we didn't pay much attention for two reasons. The first is that the European Union does not allow a closed circuit of events like in the NBA, for example.
"As the Portuguese Football Federation is against this, and as part of UEFA, we cannot participate in anything that is against the principles and rules of the European Union and UEFA.
"If that goes forward, something that I have a lot of doubts about, UEFA will not end and it is certain that they will continue to have evidence. It must be recognized that the events organized by UEFA are the official events.
"We are not concerned with being or not, we are in the Champions League and we hope to continue to be for many years."