Real Madrid are reportedly concerned by Isco's plummeting value, which has already dropped by around £13m since the start of the season.
The Spain international has fallen down the pecking order during Santiago Solari's near-four months in charge at the Bernabeu, failing to start a single league game since the end of October.
Isco recently said that he has been harshly treated by Solari, but the new man in the dugout is believed to have the full backing of the board.
However, AS claims that the 26-year-old's valuation is steadily decreasing because of his lack of minutes, dropping from £78m last summer to somewhere in the region of £65m with three months of 2018-19 to go.
Manchester City, Juventus and bitter rivals Barcelona have been credited with an interest in Isco, but all three suitors know about the player's issues with Solari and will use that to their advantage if it gets as far as negotiating a deal with Madrid.
Isco, under contract until 2022, is currently nursing a back injury which is allegedly related to the stress of his situation.