Significant Premier League clubs sent their scouts to watch Porto's Champions League qualifying clash against Krasnodar.
The game, which the Portuguese giants lost on aggregate, was watched by scouts from Leicester City, Manchester United, Manchester City, Chelsea, Watford, Southampton and others.
It is unclear if they were present to watch a certain player or get a scope for the talent around Europe.
Porto are often seen as a club with talented youngsters who may be ready to make a step up to the Premier League.
Among those linked with moves to England are Moussa Marega and Alex Telles.
