Inter Milan chief Walter Sabatini admits Joao Mario is unsettled.
The Portugal midfielder has been linked with Manchester United and PSG ahead of the winter market.
Inter paid £40m to Sporting for Mario, 24, in 2016 and would look to recoup that fee.
Sabatini said: "Joao has some issues with the lack of playing time.
"We don't want to lose him. He is our player and we want to keep him."