Bruno Alves has admitted that he has had offers to leave Porto but added that it would take something big to get him to depart the Portuguese champions.
The defender has been strongly linked with a move to Aston Villa in recent weeks while Real Madrid, Barcelona and Inter Milan are all said to be interested.
The 27-year-old has been a late bloomer in world football after being loaned out by Porto on three separate occasions before he finally stamped his authority on the first-team in 2006/2007 season.
Alves saw his stock rise at the weekend when he kept Portugal's faint hopes of qualifying for the World Cup in South Africa next summer alive when he headed a stoppage time winner against Albania.
"It is normal that other European clubs are monitoring our work because of the seasons we have enjoyed," he said.
"I am living during a very good time in my career and if any of the existing offers materialise it will have to be a very good
for me and FC Porto.
"I cannot say anything else because there is nothing concrete yet."