The 17-year-old Edinburgh derby matchwinner has attracted interest from the Premier League with both Manchester City and Southampton linked with moves for the defender.
However, according to the Scottish Sun, Hearts wouldn't net the whole transfer fee if Hickey is sold due to the deal which brought him to the club in the first place.
The Tynecastle side recruited the player from Celtic in the summer of 2018, but instead of paying a compensation fee the club agreed to a sell-on clause of 30 per cent.
Since May, Hickey has become a key member of the Hearts first-team. An impressive showing in the Scottish Cup final as a 16-year-old against James Forrest reportedly brought about interest from down south.
This campaign he has maintained his importance, playing left-back, right-back, centre-back as well as wing-back. He was sent off in the first game of the league season against Aberdeen but netted the winner at Hibs last month.
With his current deal running until 2021, Hearts are keen to tie the player down on an improved contract.