The Portugal international has been with the Ligue 1 giants since their promotion to the French top tier after completing a big money switch from Porto.
And even though he’s a key player at the Stade Louis II, the Mediterranean outfit are reportedly looking to offload him as they quest to balance the books after a mega spend.
A £14m fee and his £110,000-per-week wages removed from their books would go some way to easing financial concerns.
Arsenal are believed to be interested, with Arsene Wenger having already missed out on long-term target Morgan Schneiderlin this summer.
Monaco have also sold players such as James Rodriguez in recent times and have also allowed Radamel Falcao to make two successive loan moves away due, in part, to his massive salary.