Porto are demanding premium price for Jackson Martinez.
The Daily Express says potential suitors have been handed a £40million price tag if they want to secure Martinez.
Liverpool and Arsenal are both said to be interested in the front man, who has been in top form this season and bagged in the Champions League last match day.
It is believed that Martinez wants to move on from Porto at the end of the current season but the Reds are looking to push through a move sooner rather than later.
