Martinez hints that he may leave Porto

The Colombia international scored 26 times in 30 Primeira Liga matches last season and has seven goals to his name from nine top-flight fixtures this campaign.

Martinez, who joined Porto from Mexican side Chiapas in 2012, has revealed he would welcome a move - the likes of Chelsea and Napoli are said to be interested - if the conditions were right.

"The years are passing and one day I hope to make a good transfer," he told Record.

"It clearly depends on Porto, a club that sells its players so well.

"Leaving or staying depends on Porto, but I will only go if there is something concrete."