The 24-year-old has been a hit in the Eredivisie since joining PSV from Litex Lovech in a £3million deal last year.
The Daily Mail reports that Cologne are also interested in the Bulgarian international.
The 24-year-old has been a hit in the Eredivisie since joining PSV from Litex Lovech in a £3million deal last year.
The Daily Mail reports that Cologne are also interested in the Bulgarian international.
